How to Change an Image's Aspect Ratio
Quick answer: to change an image's aspect ratio, open it in the editor above and tap a shape under Ratios, such as 4:5, 9:16 or 16:9. Then choose a method under How to Change the Shape. Photo only trims the photo to the new shape. Add background keeps every pixel and fills the gap with a blurred copy, a colour or a mirror image. Press Download and you are done. Everything is processed here itself, nothing is uploaded to our servers.
A 4032 × 3024 phone photo cropped to 4:5 comes out at 2419 × 3024 and keeps 60.0% of the picture. Fit it to 4:5 instead and nothing goes. The frame grows to 4032 × 5040 around the untouched photo.
- Open your photos. Drop images onto the box above, click it to browse your device or press Ctrl+V to paste one. JPG, PNG, WebP, GIF and BMP open in any current browser and HEIC opens in Safari. A batch takes up to 50 images.
- Pick the new shape. Tap a shape under Ratios, such as 4:5, 9:16 or 16:9. Type any other shape into Custom ratio, press Portrait ⇄ Landscape to turn it on its side or choose a platform from Platform and print presets.
- Choose crop, background or stretch. Under How to Change the Shape, pick Photo only and drag the bright window over the part that should stay. Pick Add background to keep every pixel and fill the space with Blurred photo, Colour, Transparent or Mirror. Stretch pulls the whole photo to the new shape instead.
- Download. A preset with a published size adds Saved Size, already set to Exact preset for the platform's pixels. Tap Full quality to keep every pixel instead. Then pick a format under Save As. Press Download. A batch gets Download N Images as ZIP instead. Each file keeps its name with the ratio and -aspect-ratio-changer-collagephotoapp.com added.
Nothing saves until you press Download. Try five ratios, flip between modes, drag the window to one edge and back. Your original file sits untouched on your device the whole time. The ↺ Reset and start again button clears the editor when you want a clean slate.
What This Changer Does That Others Skip
In November 2026 we went through ten of the pages that rank for this search. We read their copy and their structured data and, where the tool runs in the browser, its code. Seven are really about pixel dimensions and treat shape as an afterthought. Seven send your photo to a server before doing anything. One says it keeps files there for up to six hours. The pages built for ratio changes have their own gaps. One shrinks your photo to under a third of its pixels when it pads: fit a 4032 × 3024 shot to 9:16 there and the photo comes back at 2268 × 1701, 31.6% of what you gave it. One takes custom ratios in whole numbers only, so 1.91:1 and 2.39:1 are out of reach. One saves PNG and nothing else. None of the ten tells you how much of your photo a change throws away or how a print shape cuts a phone photo. Here is what this one does, free and entirely inside this page.
- 13 ratio buttons under Ratios: 1:1, 4:5, 3:4, 2:3, 9:16, 16:9, 4:3, 3:2, 5:4, 1.91:1, 21:9, 3:1 and A4
- A Custom ratio box that reads 2.39:1, 16x9, 16/9 or a single decimal like 1.85, plus a Portrait ⇄ Landscape button that turns any ratio on its side
- Platform and print presets for Instagram, Facebook, X, LinkedIn, Pinterest, YouTube, TikTok, WhatsApp, Print and Screen, checked in November 2026
- Match each photo's orientation, so landscape photos get the wide form of a ratio and upright photos the tall form
- Photo only, a crop with a draggable window, a Zoom slider from 1× to 4×, zoom buttons and pinch zoom on the preview, a Close-up view and a Center button
- Add background with Blurred photo, Colour, Transparent or Mirror filling the open space, plus a From photo colour taken from the photo's own edges
- A Blur slider from 1 to 100 and a Border slider up to 20% of the frame's short side
- Live readouts of the share a crop keeps, the share of the frame a fit fills and how much wider or taller Stretch makes everything
- Show grid with rule-of-thirds lines, plus arrow keys to nudge the framing
- Full quality output that never shrinks the photo, plus Exact preset for a platform's published pixels, switched on by itself when a preset has a size
- Batch of up to 50 images where every photo keeps its own position and zoom
- Changes Apply To with All images, Only this image and Copy to all
- One ZIP for a batch, with the new ratio written into every file name
- Save As Same as original, JPG, PNG or WebP, with JPG at quality 100 and WebP at 100 by default
- Animated GIFs keep every frame and its timing
- Copy Image puts a PNG on the clipboard where the browser allows it
- Downloads without EXIF camera data or GPS location
- Runs on your device with no upload, no account and no watermark
Aspect Ratio in Plain Numbers
An aspect ratio is a shape written as two numbers, width first. 4:3 means four units across for every three down, whatever the units happen to be. Wikipedia's entry on aspect ratio puts it the same way: two numbers separated by a colon, width:height. A 4032 × 3024 photo and a 400 × 300 thumbnail share one shape. They differ only in how many pixels fill it.
Pixel count is one question, the one the Image Resizer answers. Shape is the other. This page deals with shape alone.
Reading a Ratio Like 1.91:1
Divide the first number by the second and every ratio becomes a single decimal you can compare. 16:9 is 1.778. 4:5 is 0.8. A square is exactly 1. Above 1 the shape lies down as a landscape. Below 1 it stands up as a portrait.
Some shapes only make sense as decimals. Instagram's widest feed post is 1080 × 566, which works out at 1.908. In whole numbers that is 540:283, a ratio nobody could picture. So people round it to 1.91:1 and read it as 1.91 times as wide as it is tall. Cinema does the same with 2.39:1.
Two labels can also describe one rectangle. 16:9 and 1.78:1 are the same shape. So are 8×10 and 4:5, which is why an 8×10 print and an Instagram portrait post need the same crop. Spot the match early and one crop serves both.
The Custom ratio box reads the forms people actually type: 2.39:1, 16x9, 16/9 or a lone decimal like 1.85, which it treats as 1.85:1. Portrait ⇄ Landscape turns any ratio on its side, so 16:9 becomes 9:16 in one tap. The tool stops at 10:1 wide and 1:10 tall. Past that a photo turns into a ribbon.
Finding Your Photo's Current Shape
Open a photo and the preview readout names its shape before you touch a thing, in the form Original W × H (shape). When the pixel counts reduce to small whole numbers you get the exact ratio: 4032 × 3024 reads as 4:3. When they don't, the tool finds the nearest shape people know by name and puts about in front of it. A screenshot from an iPhone 15, whose screen Apple lists at 2556 by 1179 pixels, reads as about 9:19.5. A sheet of A4 at 210 by 297 millimetres reads as about 1:1.414 (A4). A shape with no famous neighbour shows up as a plain decimal.
Knowing where you start tells you the price before you pay it. A 4:3 photo headed for 4:5 loses a slice off each side. A 16:9 video still headed for 9:16 loses most of the frame. The next section puts a number on every common pair.
Crop, Fit or Stretch
A new shape means the photo and the frame disagree, so something has to give. Part of the picture goes. Or empty space appears around it. Or everything in it bends. Those are the three choices under How to Change the Shape and each one suits a different photo.
Photo Only Crops and the Share They Keep
Photo only cuts the biggest window of the new shape the photo can hold. In the preview that window glows bright over a dimmed copy of the whole photo, so you see exactly what leaves. Drag it to choose what stays. The Zoom slider runs from 1× to 4× and closes the window around a face or a product. Center puts it back in the middle and keeps the zoom. The − and + buttons on the preview zoom as well. On a phone, pinch the window. Close-up, above the preview, fills it with only what stays. Show grid draws rule-of-thirds lines over the preview, handy for parking a pair of eyes on the top line.
At Full quality a crop copies the window pixel for pixel, so nothing gets scaled or softened. That makes Zoom a trade. Crop a phone photo to a square at 2× and the download comes out at 1512 × 1512, 18.8% of the original. At the full 4× it shrinks to 756 × 756. Tight framing costs pixels.
How much a crop keeps depends only on the two shapes, never on the photo's size. The table runs the common pairs at zoom 1. Find the shape you have on the left and read across to the shape you want.
| Your photo | To 1:1 | To 4:5 | To 3:4 | To 9:16 | To 16:9 | To 2:3 | To 1.91:1 |
|---|---|---|---|---|---|---|---|
| 4:3 (phone camera, landscape) | 75.0% | 60.0% | 56.3% | 42.2% | 75.0% | 50.0% | 69.8% |
| 3:4 (phone camera, upright) | 75.0% | 93.8% | 100.0% | 75.0% | 42.2% | 88.9% | 39.3% |
| 3:2 (most interchangeable-lens cameras) | 66.7% | 53.3% | 50.0% | 37.5% | 84.4% | 44.4% | 78.5% |
| 16:9 (video frame, wide phone mode) | 56.3% | 45.0% | 42.2% | 31.6% | 100.0% | 37.5% | 93.1% |
| 1:1 (square) | 100.0% | 80.0% | 75.0% | 56.3% | 56.3% | 66.7% | 52.4% |
A few cells deserve a second look. An upright phone photo going to 4:5 keeps 93.8%, a trim you will barely notice. The same photo going to 1.91:1 keeps 39.3%. A 16:9 frame grab turned into a 9:16 Story keeps 31.6%, under a third. Once a cell drops below half, a crop stops being a trim and becomes a different picture. Below half, Add background is usually the better choice.
Add Background Around the Whole Photo
Add background keeps every pixel and builds a bigger frame of the new shape around it. At Full quality the photo stays at its own size and only the frame grows. A 4032 × 3024 photo fitted to 9:16 sits inside a 4032 × 7168 frame. The photo itself is untouched. The extra 4144 rows of height are fill.
The crop table reads the other way round for Add background. The share a crop keeps is the share of the frame the photo covers when you fit it instead. That 4:3 photo fitted to 9:16 covers 42.2% of the frame, the same 42.2% a crop would keep. The line under the preview says it outright: Photo fills N% of the frame.
Drag the photo to slide it along the open side. A landscape shot in a tall frame can sit high with room underneath for a caption. Or it can sit low under a band of sky. Center puts it back in the middle. The Border slider adds an even margin from 0 to 20% of the frame's short side. Fit a phone photo into a square with a 10% border and you get 5040 × 5040: the photo at full size with at least 504 pixels of margin on every side.
Stretch and How Far It Bends Faces
Stretch pulls the whole photo to the new shape. Nothing is cut and nothing is added, so every circle turns into an oval. At Full quality it lengthens whichever side the new shape needs and never shrinks either one. A phone photo stretched to 16:9 becomes 5376 × 3024. The readout says 33% wider.
A third wider is a lot on a face. Cheekbones spread, eyes drift apart and a friend gains a jaw they never had. The table shows how hard the common changes pull.
| From | To | A circle comes out | The readout says |
|---|---|---|---|
| 3:4 | 4:5 | 1.07 times as wide as tall | 7% wider |
| 4:3 | 3:2 | 1.13 times as wide as tall | 13% wider |
| 4:3 | 1:1 | 0.75 times as wide as tall | 33% taller |
| 4:3 | 16:9 | 1.33 times as wide as tall | 33% wider |
| 1:1 | 16:9 | 1.78 times as wide as tall | 78% wider |
| 4:3 | 9:16 | 0.42 times as wide as tall | 137% taller |
| 16:9 | 9:16 | 0.32 times as wide as tall | 216% taller |
Stretch still has honest work. A gradient, a cloudless sky, a texture of sand or brushed metal: none of them carries a shape your eye can check. Small pulls get away with more too. Going from 3:4 to 4:5 reads as 7% wider and a crowded street scene gives the eye little to measure against. Anything with a person, a plate or a logo in it belongs in Photo only or Add background.
Changing Aspect Ratio Without Cropping
Most people who search for this want the whole photo in a new shape with nothing cut. Add background does exactly that. What goes into the open space around it is up to you. The tray labelled "Fill the space with" offers four answers.
Picture a bakery owner with a landscape shot of the morning's croissants and a Story to post before the doors open. Cropping a 4:3 photo to 9:16 keeps 42.2%, so more than half the tray disappears. Fit it with Blurred photo instead and the whole tray sits in the middle of the Story inside a soft wash of golden crust. At the Story or Reel preset size of 1080 × 1920 the photo lands at 1080 × 810, leaving 555 pixels of blur above it and the same below. Plenty of room for the opening hours.
Choosing a Fill
| Fill | What goes in the space | Looks right for | Watch out for |
|---|---|---|---|
| Blurred photo | A soft, enlarged copy of the same photo. Blur runs from 1 to 100 and starts at 60 | Stories, Reels and feed posts, where plain bars would look like a mistake | Low strength, where the copy still reads as a picture and competes with the real one |
| Colour | A flat colour: White, Black, Cream, Charcoal or anything from the picker | Product shots on white, gallery-style mounts, a brand colour | Photos whose edges are busy, where the hard line between photo and colour shows |
| From photo | The average colour of the photo's own edges, worked out for each photo | Plain walls, open sky, studio backdrops, anything with a calm border | Mixed edges, which average out to a muted in-between colour |
| Transparent | Nothing at all. The open space stays see-through | Logos, cut-outs and stickers saved as PNG or WebP | JPG, which has no transparency and saves the space as white |
| Mirror | Flipped copies of the photo tiled outward, so each edge meets its own reflection | Water, foliage, gravel, crowds seen from far away | Faces and lettering, which turn into inkblot tests |
A seller with square product shots runs into this every week. The feed favours 4:5 and every photo is 1:1. Fit a 2000 × 2000 shot into the Instagram Portrait post preset with White and the bottle stays whole on a 1080 × 1350 frame, with a 135-pixel white band above and below. At Full quality the same fit comes out at 2000 × 2500. Cropping instead keeps 80.0% and trims the sides, which is exactly where a label wraps around a bottle.
From photo is the quiet one. It samples a thin band around the photo's edges and averages it, so a portrait shot against a grey studio wall gets a grey that continues the wall. Mirror is the bold one. Each edge meets its own reflection, so a lake or a hedge carries on past the frame almost invisibly. Put a face near the edge and you get a twin. Transparent suits a logo heading for a website, as long as you save it as PNG or WebP.
Why AI Scene Extension Needs a Server
Some pages that rank for "without cropping" use generative AI to paint new scenery past the edges: more beach, more sky, an invented second half of a sofa. It can look convincing. It also needs a large AI model to do the painting. That model either runs on a company's servers or arrives as a download of several gigabytes. Either the photo leaves your hands. Or you wait out a download measured in gigabytes before the first edit.
This tool keeps one promise: nothing leaves your device. So it fills the space only with what the photo already holds, whether that is a blur of its own colours, a reflection of its edges or a colour sampled from its border.
Invented pixels carry a cost people forget. The model guesses what was outside the frame. A guessed hand at the edge of a family photo can grow a sixth finger. A guessed shopfront can sprout a sign in no known alphabet. A fill makes no claim about what was there, which is the honest answer when nobody photographed it.
Aspect Ratios by Platform in 2026
We checked every row below against each platform's own help pages in November 2026. Where a platform publishes no pixel size, the table says so instead of guessing. The Platform and print presets select in the editor holds the same shapes, grouped by platform. Exact preset switches on only for the ones with a published size. The rest change the shape and keep your photo's own resolution.
Size charts rot faster than people expect. Some still list Twitter Fleets, which ended on 3 August 2021. Others still list IGTV covers, though the IGTV app closed in March 2022. Check the date on any chart before you trust it, this one included.
| Platform | Placement | Ratio | Published size | Outside the range or other limits |
|---|---|---|---|---|
| Feed post | 1.91:1 to 3:4 | Up to 1080 wide, 1080 × 566 to 1080 × 1440 | Cropped to a supported ratio. Wider than 1080 shrinks to 1080, under 320 wide is enlarged to 320 | |
| Story or Reel | 9:16 | 1080 × 1920 in Meta's Stories ad specs | No published rule | |
| Feed image | 4:5 | 1440 × 1800 | Meta allows a 3% tolerance on the ratio | |
| Video feeds image | 1.91:1 to 4:5 | 1440 × 1440 at 1:1, 1440 × 1800 at 4:5 | Meta allows a 3% tolerance on the ratio | |
| Image post | 3:1 to 4:5 | At least 552 × 276, 1080 wide recommended, 5 MB upload limit | Centred and cropped | |
| Multi-photo post | No taller than 4:5 | No published size | Up to 20 photos in one post | |
| X | Single photo | 2:1 to 3:4 shown in full | No published size | Not shown in full. Up to 4 photos per post |
| Standard Pin | 2:3 | 1000 × 1500 | Pins taller than 2:3 might get cut off in feeds | |
| YouTube | Video thumbnail | 16:9 | 3840 × 2160 recommended, 640 wide minimum | JPG or PNG, 2 MB from mobile, 50 MB from desktop |
| YouTube | Shorts thumbnail | 9:16 | 2160 × 3840 recommended, 640 tall minimum | JPG or PNG, 50 MB from desktop |
| YouTube | Channel banner | 16:9 | 2560 × 1440 recommended, 2048 × 1152 minimum | 1235 × 338 safe area at the minimum size, 6 MB or smaller |
| TikTok | Photo | 9:16, commonly recommended | No official photo spec found | No published rule |
Instagram's help page on photo resolution is the plainest spec of the lot. Feed photos go up at a width of up to 1080 pixels and keep their original resolution when the ratio sits between 1.91:1 and 3:4, which is 1080 × 566 to 1080 × 1440. Outside that range Instagram crops. Narrower than 320 pixels, it enlarges the photo to 320.
3:4 is a recent arrival. Adam Mosseri announced native 3:4 support, which 9to5Mac reported on 29 May 2025. Before that the tallest feed post was 4:5. The profile grid has shown tall rectangles instead of squares since January 2025. Guides put those tiles at 3:4, though Instagram hasn't published the figure itself, so treat 3:4 as likely rather than official. If it holds, a 4:5 post shows 93.8% of itself on the grid and loses a sliver from each side. Keep the subject off the far left and right.
A 9:16 frame posted to the feed falls outside the range, so the app crops it. Cut to 3:4, the tallest shape the feed keeps, a 9:16 frame holds 75.0% of itself. Make that crop here first with the Tall post preset and you choose what goes, not the app. The Square post preset gives 1080 × 1080 and the Portrait post preset gives 1080 × 1350. Instagram's resolution page lists no Story size. The Story or Reel preset uses 1080 × 1920, the size Meta's own Stories ad requirements recommend.
Facebook and LinkedIn
Meta's Ads Guide now gives Facebook Feed images one shape, 4:5 at 1440 × 1800, with a 3% tolerance on the ratio. That tolerance is generous. A photo a hair off 4:5 still passes, so a near miss needs no second crop. Its Facebook video feeds spec still takes 1.91:1 to 4:5 and gives 1440 × 1440 for a square.
LinkedIn's image guidance asks for at least 552 × 276 pixels, recommends 1080 pixels wide and caps uploads at 5 MB. It takes ratios from 3:1 to 4:5 and centres and crops anything outside them. A 9:16 phone photo cut down that way keeps 70.3% and loses slices off its top and bottom, which is where foreheads and feet live. A post with several photos renders no taller than 4:5 and holds up to 20. The LinkedIn presets give 1080 × 1350 for portrait.
X, Pinterest, YouTube and TikTok
X shows a single photo in full when its ratio falls between 2:1 and 3:4. A post holds up to four photos. X publishes no pixel size, so its presets change the shape and leave the resolution alone.
Pinterest's product specs recommend 2:3 at 1000 × 1500 and warn that Pins with a ratio taller than that might get cut off in feeds. A landscape phone photo cropped to 2:3 keeps 50.0%. An upright one keeps 88.9%, an easy trim.
YouTube's thumbnail help recommends 3840 × 2160 for videos and 2160 × 3840 for Shorts, aiming at 16:9 and 9:16. Video thumbnails need a width of at least 640 pixels and Shorts thumbnails a height of at least 640. Files go up as JPG or PNG. A video thumbnail can be up to 2 MB from a phone. From a desktop, both kinds can be up to 50 MB. Channel banners follow a separate page: 2560 × 1440 recommended, 2048 × 1152 minimum and a 1235 × 338 safe area at that minimum size, in a file of 6 MB or less. Keep faces and words inside that strip.
TikTok publishes no photo spec we could find. 9:16 is the full-screen frame and the shape commonly recommended, so that is what the Full-screen photo preset uses. The WhatsApp Status preset uses 9:16 as well.
Print Sizes and the Shapes They Need
Prints are where a ratio mismatch costs real money. A lab that receives the wrong shape has to trim it or leave white edges. You find out when the envelope arrives. The table gives each common size as a ratio and shows how much of a photo survives, for an upright phone photo at 3:4 and an upright camera photo at 2:3.
| Print size | Shape | Width ÷ height | Phone photo (3:4) keeps | Camera photo (2:3) keeps |
|---|---|---|---|---|
| 4×6 in | 2:3 | 0.667 | 88.9% | 100.0% |
| 5×7 in | 5:7 | 0.714 | 95.2% | 93.3% |
| 8×10 in | 4:5 | 0.8 | 93.8% | 83.3% |
| 8.5×11 in (US Letter) | 17:22 | 0.773 | 97.1% | 86.3% |
| 11×14 in | 11:14 | 0.786 | 95.5% | 84.8% |
| A4 (210×297 mm) | 1:1.414 | 0.707 | 94.3% | 94.3% |
Every size in the table sits between 2:3 and 4:5. A4 is the only one built on an irrational number. Every A size shares the ratio 1:√2, about 1:1.414, chosen so that cutting a sheet in half gives the next size down in the same shape. That is the rule behind the ISO 216 standard, so the A4 button and the A4, A3 and other A sizes preset cover the whole family in one go. A4 keeps 94.3% of an upright phone photo.
Why a 4×6 Print Trims a Phone Photo
A parent orders a stack of 4×6 prints from a weekend of phone photos. The beach shots come back fine. The group photo by the car comes back with three hairlines sliced off. Nothing went wrong at the lab. The phone shot 4:3. The paper is 2:3 upright and 3:2 lying down. The two shapes simply disagree.
A 4×6 print keeps 88.9% of a phone photo. On a 4032 × 3024 landscape the print shape needs 4032 × 2688, so 336 rows of pixels have to go. Centred, that is 168 off the top and 168 off the bottom. A tightly framed group loses its hairlines first. A 5×7 is kinder at 95.2% and an 8×10 keeps 93.8%.
The fix takes a minute. Load the prints here, pick the 4×6 preset under Print and tick Match each photo's orientation so landscape shots get 3:2. Then step through and drag each window until every head is in. The lab receives files that already match its paper and has nothing left to guess.
Camera owners get off lightly with 4×6. A 3:2 camera photo fills it exactly and keeps 100.0%. It is 8×10 that bites them: only 83.3% of the frame survives.
Camera, Phone and Screen Shapes
Every photo starts life in the shape of the thing that took it. Knowing those shapes explains most of the cropping surprises above. We checked each row in November 2026 against the source named beside it.
| Source | Shape | Checked against |
|---|---|---|
| iPhone Camera app | 1:1, 4:3 and 16:9 under Aspect | Apple Support |
| Pixel Camera | Full image (4:3) or Wide crop (16:9) | Pixel Camera Help |
| Samsung Galaxy camera | 3:4, 9:16, 1:1 and Full | Samsung Support |
| 35 mm film, 36 × 24 mm frame | 3:2 | Wikipedia |
| Most point-and-shoot, Four Thirds and Micro Four Thirds cameras | 4:3 | Wikipedia |
| Full HD at 1920 × 1080 and 4K UHD at 3840 × 2160 | 16:9 | Wikipedia |
| Monitors and laptops before most moved to 16:9 | 16:10 (1.60:1) | Wikipedia |
| Ultrawide monitors | Sold as 21:9, really 64:27, about 2.37:1 | Wikipedia |
| Cinema screens | 1.85:1 and 2.39:1 | Wikipedia |
| iPhone 15 screen, 2556 × 1179 | about 19.5:9 | Apple tech specs |
What Phones and Cameras Shoot
The iPhone Camera app offers 1:1, 4:3 and 16:9 under Aspect, according to Apple Support. Recent Pixel phones call their two choices Full image (4:3) and Wide crop (16:9), names that say plainly which one trims. Samsung's Galaxy camera lists its ratios upright: 3:4, 9:16, 1:1 and Full. A 12.2 megapixel photo at 4032 × 3024 is the 4:3 example this page keeps coming back to.
Dedicated cameras split along older lines. Wikipedia ties 3:2 to 35 mm film and its 36 × 24 mm frame, the shape full-frame digital cameras inherited. It ties 4:3 to most point-and-shoot cameras plus the Four Thirds and Micro Four Thirds systems. So a 3:2 camera file and a 4:3 phone file from the same wedding need different crops for the same album page.
Screens, Video and Cinema
Screens mostly settled on 16:9, the shape of Full HD at 1920 × 1080 and 4K UHD at 3840 × 2160. Monitors and laptops went through 16:10 before most moved to 16:9. Ultrawide monitors are sold as 21:9, a marketing name for 64:27, roughly 2.37:1. Cinema runs wider still. Theatres commonly show 1.85:1 and 2.39:1. The Custom ratio box takes both.
Phones went tall. Apple lists the iPhone 15 screen at 2556 × 1179 pixels, which the readout calls about 19.5:9. A screenshot keeps that shape, so a screenshot posted as a 9:16 Story needs a trim or a fill too. Cropped, it keeps 82.0%.
Keeping Every Pixel When the Shape Changes
Full Quality or Exact Preset
Saved Size has two settings. Full quality, the default, never shrinks your photo. A crop copies the window pixel for pixel. Add background leaves the photo at its own size and grows the frame around it. Stretch lengthens one side to reach the new shape and leaves the other alone.
Exact preset W × H gives the exact pixels a platform publishes. Pick the Instagram Portrait post preset and the editor switches to Exact preset by itself, so a crop or a fit both come out at 1080 × 1350. Saved Size appears only when the chosen preset has a published size. Choose an X preset and it stays hidden, because X publishes a range of shapes rather than a size.
Tap Full quality for anything you might print or reshape again later. Keep Exact preset when a platform publishes a size and you want the file to arrive exactly as it will be shown. Instagram shrinks anything wider than 1080 anyway, so a file made at 1080 × 1350 already arrives at the width the feed shows.
Exact preset has one catch: it can enlarge a small photo. A screenshot 640 pixels wide sent to 1080 × 1350 has to be blown up and the editor warns you when that happens. Enlarged pixels look soft. Full quality never does that to a crop.
The Memory Ceiling on Phones
Add background at Full quality makes big files. The 4:3 phone photo fitted to 9:16 becomes 4032 × 7168. That is 28.9 megapixels, more than twice the 12.2 it started with. Browsers allow a page only so much memory for one picture. Apple draws the line tightest.
An iPhone or iPad on iOS 17 and earlier stops at 16,777,216 pixels, about 16.8 megapixels. From iOS 18 the tool allows 33,554,432, about 33.6. Laptops, desktops and Android phones get 50,000,000. When a result would pass the ceiling, the tool scales it down just enough to fit, keeps the shape and says so in the editor. That 9:16 fit saves at 3072 × 5461 on iOS 17 and at full size on iOS 18.
Crop almost never meets the ceiling, because cropping only ever removes pixels. Add background and Stretch are the ones to watch, along with a wide Border. If a phone keeps scaling a result down, open the same photo on a laptop and the full 50 megapixel allowance applies.
Reshaping a Whole Batch
A batch holds up to 50 images. In a batch, Changes Apply To decides where each edit lands. All images sends it across the set. Only this image keeps it to the photo on screen. Copy to all copies the current photo's settings onto every other one.
The part that matters most: every photo keeps its own position and zoom. Set 4:5 for forty christening photos at once, then step through and drag each window onto the right face. The ratio is shared. The framing belongs to each photo. A window you place on photo twelve stays there while you fix photo thirteen.
Mixed orientation is the other batch headache. Tick Match each photo's orientation and landscape photos get the wide form of the ratio while upright ones get the tall form. Choose 9:16 and a landscape 4032 × 3024 shot comes out at 4032 × 2268, which is 16:9, keeping 75.0% instead of 42.2%. Perfect for a slideshow or a print order. Wrong for a run of Stories, where every frame has to stand up.
Press Download N Images as ZIP and the set arrives as one archive named Image Aspect Ratio Changer - CollagePhotoApp.com.zip. Every file inside keeps its own name plus the ratio and -aspect-ratio-changer-collagephotoapp.com, so beach.jpg at 4:5 becomes beach-4x5-aspect-ratio-changer-collagephotoapp.com.jpg. Two photos both called beach.jpg would collide, so the second becomes beach-2-4x5-aspect-ratio-changer-collagephotoapp.com.jpg. A single photo downloads on its own under the same pattern.
The batch runs single file. The tool opens, draws and lets go of one photo before it starts the next, so 50 photos never crowd into memory together.
Formats, Transparency and Animated GIFs
JPG, PNG, WebP, GIF and BMP open in any current browser. HEIC, the iPhone's camera format, opens in Safari. On an iPhone or iPad it opens in Chrome, Edge and Firefox too, because there they run on Safari's engine. Chrome, Edge, Firefox and Samsung Internet on Windows, Mac and Android can't decode it, so open HEIC files in Safari or convert them to JPG first.
Save As offers Same as original, JPG, PNG and WebP. Same as original keeps your format with two exceptions: BMP saves as PNG and HEIC saves as JPG, because browsers can write neither. JPG starts at quality 100, the top of the scale. WebP starts at 100, which Chrome writes as lossless WebP.
Transparency has one trap. The Transparent fill leaves the open space see-through. Only PNG and WebP can carry that. Save a transparent fit as JPG and the space comes out white, because JPG has no way to store nothing. A logo on a see-through 1:1 tile belongs in PNG.
An animated GIF keeps every frame and its timing when you save it as Same as original. A wide reaction loop fitted to 9:16 with Blurred photo still loops at its own speed, every frame given the same new shape. Decoded, each frame is a full picture, so the tool accepts GIFs whose frames add up to 400,000,000 pixels, counted at the larger of the old and the new frame size. Cropped, that is 3,086 frames of a 480 × 270 clip. Fitted to 9:16, the same clip gets 976.
Privacy: What Stays on Your Device
Everything is processed here itself, nothing is uploaded to our servers. Your photo travels from your disk into this page and back out to your downloads folder. No copy goes anywhere in between, so there is nothing for us to keep, scan or lose.
Downloads carry no EXIF camera data and no GPS location, because the tool writes each file fresh from pixels. A photo taken at your child's school gate, reshaped to 9:16 for a family Story, no longer says where the gate is. Keep the original if you want the location for your own albums.
The tool applies EXIF orientation before any reshaping. It turns a phone photo stored on its side with an orientation tag upright first, so the 4:5 window you see is the 4:5 window you get. Copy Image puts a PNG on your clipboard where the browser allows it. In a batch the button reads Copy This Image. That copy stays on your device too.
Five Ratio Changes That Go Wrong
Trusting the Centre on a Group Shot
Photo only starts with the window in the middle. For a single portrait that is usually right. For ten people lined up across a 4:3 photo it is a disaster: a 9:16 crop keeps 1701 of the 4032 columns and both ends of the row vanish. Drag the window to pick your side. Better still, switch to Add background with Blurred photo and keep everyone. When the preview has focus, the arrow keys nudge the window a step at a time and the plus and minus keys zoom.
Stretching a Round Logo Into an Oval
Stretch tempts because it fills the frame with no bars and no loss. A round logo on a square tile, pulled out to a 16:9 header, comes out 1.78 times as wide as it is tall. The readout calls that 78% wider. Customers who know the round tin will spot the oval one at a glance. Fit the tile with From photo or Colour and the logo keeps its shape while the header still fills edge to edge.
Reshaping a Copy That Was Already Cropped
Crop a phone photo square for the feed and you get 3024 × 3024. A week later you want a 16:9 header from it. Cut from the square, 16:9 gives 3024 × 1701, just 42.2% of the original photo. Cut from the original, it gives 4032 × 2268 and 75.0%. The square already threw away the sides the header needed. Every crop is final the moment you save it, so always start again from the original file.
Fitting a Tall Photo Into a Wide Banner
Add background keeps everything, but in an extreme mismatch everything is a postage stamp. An upright 9:16 photo fitted into a 3:1 banner covers 18.8% of it. The rest is fill. On a website header that reads as a narrow slice of photo floating in a lot of blur. For a banner, crop and drag the window to the band that matters. Or start from a landscape photo.
Making One File Serve Every Placement
A single 4:5 file posted everywhere looks right in one place at a time. On X it shows in full. Shared to a 9:16 Story it floats with empty space above and below. On Pinterest it sits shorter than the 2:3 the platform recommends. Make one version per placement from the same original. It takes seconds and a batch keeps each photo's framing.
Collages are the hardest case, because a layout cut for a square breaks when the frame turns tall. CollagePhotoApp handles that inside the design: switch a square post to a Story and the design refits itself instead of chopping the edges off.
Pair It With Our Other Free Tools
The Image Resizer changes pixel size and keeps the shape, so reach for it after this page when a form wants an exact width or a file under a KB limit. Rotate Image turns sideways photos upright and levels crooked horizons. Do that first, because a tilted photo makes every crop window look wrong.
For Instagram, the Instagram Grid Maker cuts one photo into profile tiles in posting order. The Instagram Carousel Splitter slices a panorama into swipeable slides. Add Text to Photo sets a caption into the blurred band a fit leaves behind, which is the best use that band has.
For more than one photo, the Collage Maker lays several into one designed frame. Merge Images joins them in a row, a column or a grid. The Side by Side Photo Maker pairs two for a before and after. The Photobooth shoots photo strips from your camera or your saved photos.
Stories get their own guides. The walkthrough on making an Instagram Story collage covers 9:16 layouts built from several photos. The guide to adding multiple photos to an Instagram Story runs through four ways to do it, from slideshows to full collages. The roundup of the best Instagram Story maker apps compares twelve of them. For phone-only work, see how to make a collage on your phone.
CollagePhotoApp is our free app for iPhone and Android. It builds collages in six frame sizes: 1:1, 9:16, 4:3, 3:4, 5:4 and 16:9. Change the frame on a finished design and the layout refits to the new shape, something a single flat photo can't do. The store badges above and below this article link to both versions. Every tool here is listed on the free tools page and the longer guides live on the blog.
Frequently Asked Questions
What does aspect ratio mean for a photo?
Aspect ratio is the shape of a picture: its width compared with its height, always written width first. A 4:5 photo is four units wide for every five tall. Size plays no part. 1080 × 1350 and 2160 × 2700 are both 4:5. The second just holds four times the pixels. Some shapes are easier to write as a decimal over 1. 1.91:1 simply means the width is 1.91 times the height. Under 1:1 a photo stands upright. Over it, the photo lies wide.
How do I find out what aspect ratio my photo is?
Open it here and the readout names it straight away: a 12.2 megapixel phone shot reads Original 4032 × 3024 (4:3). By hand, divide the width and the height by the largest number that goes into both. 4032 and 3024 share 1008, which leaves 4 and 3. Real files rarely divide that cleanly. 1080 × 566 only reduces to 540:283, so the readout calls it about 1.91:1, the nearest shape anyone actually uses. Most phone galleries list the pixel size in a photo's details, which is all the sum needs.
Is changing the aspect ratio the same as changing the pixel dimensions?
No. The aspect ratio is the shape, while the pixel dimensions are the size. Shrink a 4032 × 3024 photo to 1008 × 756 and it is still 4:3: smaller, same proportions. This page moves the proportions themselves, from 4:3 to 4:5 or 9:16, by cropping, adding space or stretching. For a smaller pixel size or a file that has to land under a set number of KB, the Image Resizer does that job. Plenty of posts need both. Fix the shape here first, then bring the download down to size.
What aspect ratio is 1080 × 1350, 1080 × 1920 or 1920 × 1080?
1080 × 1350 is 4:5, 1080 × 1920 is 9:16 and 1920 × 1080 is 16:9. A few more that come up all the time: 1080 × 566 is about 1.91:1, the Instagram landscape post. 1000 × 1500 is 2:3, the Pinterest pin. 2560 × 1440 is 16:9, the YouTube channel banner. 1080 × 1440 is 3:4, Instagram's tallest feed post. The method never changes. Divide both numbers by whatever they share: 1080 and 1350 share 270, which leaves 4 and 5.
Does the download look exactly like the preview?
Yes. The preview and the download come from one drawing step fed the same settings. The preview draws a smaller copy sized for your screen, so it keeps up while you drag the window. The download goes back to your original file and draws it again at full size. Same framing, same fill, same colours. Only the detail grows. Nothing saves until you press Download, so you can try all 13 ratio buttons and 30 presets without a single wasted file.
How big does the frame get when the whole photo has to fit?
Big enough to hold every pixel at its own size. Add background grows the frame around the picture instead of shrinking the picture into it. A 4032 × 3024 photo fitted to 1:1 comes out 4032 × 4032. At 16:9 it becomes 5376 × 3024. At 9:16 it reaches 4032 × 7168, with the photo intact across the middle covering 42.2% of the frame. The rest needs filling. The tray labelled "Fill the space with" offers Blurred photo, Colour, Transparent and Mirror. Blurred photo is the usual pick for a Story, because it hides where the photo ends. For a product on a plain backdrop, Colour with From photo matches the background instead.
How much of a photo is lost when cropping to a new aspect ratio?
It depends on how far the shape moves. A landscape 4:3 phone photo keeps 75.0% at 1:1, 60.0% at 4:5 and just 42.2% at 9:16. Hold the same phone upright and the bill shrinks: a 3:4 shot cropped to 4:5 keeps 93.8%. Video stills pay the most. A 16:9 frame cut to 9:16 keeps 31.6%, under a third. The line beneath the preview prints the share for your own photo before you save anything. If it looks painful, Add background keeps 100%.
How do I stop the new ratio from cutting off someone's head?
Drag the bright window. In Photo only the preview dims everything the crop will drop. The bright window marks what stays. Slide it up until the top of the head clears the edge. With the preview focused, the arrow keys nudge the window in small steps and Shift makes each step bigger, which helps when you are lining up a horizon. Show grid draws rule-of-thirds lines over the photo. Eyes on the upper line nearly always look right in a portrait. Overshot? Center puts the window back in the middle. In a batch, every photo remembers its own position.
What does the Zoom slider do when I crop?
Zoom tightens the crop window, from 1×, the largest window the photo allows, up to 4×. Use it to lose a messy background or move in on a face. At Full quality the window is copied pixel for pixel, so zooming in means fewer pixels out. A 4032 × 3024 photo cropped to 4:5 gives 2419 × 3024 at 1×, 1210 × 1512 at 2× and 605 × 756 at 4×. That last one is narrower than a 1080 pixel Instagram post. The plus and minus keys zoom too, once the preview has focus. So do the − and + buttons on the preview. On a phone, pinch the window. For an exact figure, tap the number beside the slider and type it, such as 2.5. Close-up, above the preview, shows only the kept part, filling the preview. Exact preset works differently. It scales the window to the preset's exact pixels and enlarges it when the window is smaller.
Will my photo look less sharp after changing its shape?
No, not if you crop or add background at Full quality. Photo only copies the window pixel for pixel, with no scaling at all. You lose the trimmed area, never sharpness. Add background keeps the photo at its own size and builds the frame around it. The one remaining step is the save. JPG goes out at quality 100. WebP goes out at 100, the setting Chrome turns into lossless. PNG is lossless every time. Two choices do soften detail. Stretch pulls pixels apart in one direction. Exact preset can enlarge a small photo to hit a platform's exact pixels.
What pixel size comes out after changing the aspect ratio?
At Full quality, the default, nothing gets shrunk and the size follows the method. Photo only gives exactly the window it cut, so a 4032 × 3024 photo at 4:5 comes out 2419 × 3024. Add background grows the frame instead: the same photo fitted to 4:5 becomes 4032 × 5040. Stretch lengthens one side to reach the new shape and leaves the other alone. Exact preset W × H gives a platform's exact pixels, such as 1080 × 1350 for the Instagram Portrait post preset. Picking a preset with a published pixel size shows Saved Size with Exact preset already on. 13 of the 30 presets have one.
How badly does Stretch distort a photo?
Stretch bends everything in the frame by exactly as much as the shape moves. Pull a 4:3 photo to 16:9 and every face, wheel and window gets 33% wider. A round face turns into a wide oval. Pull the same photo to 9:16 and everything ends up 0.42 times as wide as it should be for its height, which the line under the preview reports as 137% taller. People look like they stepped through a funhouse mirror. Stretch only earns its place with textures, gradients, skies and abstract patterns, where nobody knows the true proportions.
What does the Blurred photo fill do and when does it look best?
Blurred photo fills the spare space with a soft, enlarged copy of the same picture, so the colours around your photo come from the photo itself. It suits a landscape shot dropped into a 9:16 Story or Reel, where flat bars would look like an error. The Blur slider runs from 1 to 100 and starts at 60. Low settings leave shapes you can still make out, like a view through a steamed-up window. At 100 only colour remains. Busy scenes such as crowds or market streets look calmer toward the top of the range.
What colour does the From photo swatch pick?
From photo takes the average colour of a thin band around your photo's edges and fills the frame with it. The eye expects the edge to carry on, which is exactly what this colour does. It works best on product shots against a plain backdrop, portraits in front of a painted wall and skies that run into the frame. The average turns muddy when the edges disagree, say blue sea down one side and orange sand along the other. Pick White, Black, Cream, Charcoal or the custom picker then. All of them sit under Colour.
How do I put a photo on a square with white borders?
Pick 1:1, choose Add background, then Colour and White. The whole photo sits on a white square, with white bands above and below a landscape shot. For an even margin all round, drag the Border slider. It runs from 0 to 20% of the frame's short side and adds the same width to all four edges. A 4032 × 3024 photo with a 10% border comes out 5040 × 5040. Nothing shrinks. The frame grows instead. The result looks like a gallery print. A white frame also keeps a busy photo from bleeding into the next post in a feed.
What does the Mirror fill do?
Mirror fills the spare space with flipped copies of your photo, laid edge to edge so every border meets its own reflection. No seam shows, because the pixels on each side of a join match exactly. It looks natural with sand, water, grass, foliage, sky and brick. It goes wrong fast with anything recognisable near the edge. A shoulder grows a twin. Writing comes out back to front. Try it on a beach shot before a group photo. When Mirror misbehaves, Blurred photo keeps the colours without the copies.
Can I make the empty space transparent?
Yes. Choose Add background, pick Transparent and set Save As to PNG or WebP. Both keep the spare space clear, ready to sit on a slide, a web page or a coloured layer in a design app. JPG has no way to store see-through pixels. A JPG download paints that space white. The trap is Same as original. Start from a JPG and you get a JPG back, white space included, so pick PNG before you press Download. Photo only and Stretch keep the clear areas inside a logo or a cut-out product shot too, provided the file goes out as PNG or WebP.
Can I move the photo inside the new frame instead of centring it?
Yes. In Add background, drag the photo along the open side of the frame. A landscape shot in a 9:16 Story slides up and down. An upright one in a 16:9 frame slides left and right. Push it toward the bottom to leave room for a caption above. Push it up to clear space for stickers below. Center puts it back in the middle. With a Border set, the photo stays inside the margin while it moves. The arrow keys nudge it too, once the preview has focus.
Can I type a custom aspect ratio like 2.39:1?
Yes. Type it into the Custom ratio box in whichever spelling you like: 2.39:1, 16x9, 16/9 or a single decimal such as 1.85, which means 1.85:1. Decimals work on either side, so 1:1.414 is fine. A comma counts as a decimal point too, which means 2,39 reads as 2.39. Each number can run from 0.01 to 1,000. The finished shape has one limit: nothing wider than 10:1 or taller than 1:10. Past that you have a ribbon, not a picture. The ratio lands in the file name as well, so 2.39:1 saves as 2.39x1.
What does the Portrait ⇄ Landscape button do?
Portrait ⇄ Landscape turns the current ratio on its side. 16:9 becomes 9:16, 4:5 becomes 5:4 and A4 upright becomes A4 landscape. It works on a typed Custom ratio as well. Most shapes already sit in the buttons both ways round, so the button mainly saves a hunt. For 1.91:1, 21:9, 3:1 and A4 it is the only route to the other orientation, which is how you get a tall 9:21 phone wallpaper or a 1:3 banner standing up. Turn a 2:3 pin around and you get 3:2, the shape of a landscape 4×6 print. For a mixed batch, Match each photo's orientation flips per photo instead.
What does Match each photo's orientation do?
It gives every photo the ratio in its own direction: landscape photos get the wide form and upright photos the tall one. Set 4:5 on a mixed batch and the upright shots come out 4:5 while the landscape ones come out 5:4. That saves a lot of picture. A 4032 × 3024 landscape cropped to 4:5 keeps 60.0%. Matched to 5:4 it comes out 3780 × 3024 and keeps 93.8%. A square photo gets the ratio exactly as set. Leave the box unticked when every file must share one exact shape, like a print order or a carousel.
How do I turn a landscape photo into a portrait one?
Pick a tall ratio such as 4:5, 3:4 or 9:16, then decide what happens to the sides. Photo only keeps an upright slice: 60.0% of a 4:3 landscape at 4:5 and 42.2% at 9:16. Drag the window onto whatever matters. Add background keeps the full landscape and fills above and below with Blurred photo, Colour or Mirror. Rotating is the wrong tool for this. A 90° turn does stand the photo up, but it lays the horizon on its side too. Save rotation for photos that were shot sideways.
Which aspect ratios does the Instagram feed show without cropping?
Instagram keeps a feed photo at its original resolution when the ratio sits between 1.91:1 and 3:4, which is 1080 × 566 to 1080 × 1440 at the full 1080 pixel width. Anything wider or taller gets cropped. Width matters as well. Instagram enlarges a photo under 320 pixels wide to 320 and shrinks one over 1080 to 1080. So a 4032 × 3024 shot uploads fine but displays at 1080 wide. The Instagram presets here, Square post, Portrait post, Tall post, Landscape post and Story or Reel, each carry an exact size for Exact preset. Instagram Help publishes the range. We checked it in November 2026.
Is 4:5 or 3:4 better for an Instagram post?
3:4 gives you the most height the feed shows, 1080 × 1440 against 1080 × 1350 for 4:5, about 7% taller. Instagram added native 3:4 in 2025. 9to5Mac reported Adam Mosseri's announcement on 29 May that year. Before then, 4:5 was the tallest option. 4:5 still wins for a photo you plan to post elsewhere too. Facebook Feed and LinkedIn both top out at 4:5, so one 4:5 file works on all three. Shot on a phone held upright? Then your photo is 3:4 already and a 3:4 post keeps 100.0% of it.
What shape are Instagram profile grid thumbnails now?
Tall rectangles, most likely 3:4. Instagram swapped the square profile grid for taller tiles in January 2025, as Social Media Today reported on 19 January. The exact 3:4 figure comes from creator guides rather than an Instagram announcement, so treat it as a strong guess. If it holds, a 3:4 post shows whole on your grid, while a square post shows only 75.0% of itself, trimmed at the sides. To plan a profile mosaic across several posts, the Instagram Grid Maker splits one image into the tiles.
What aspect ratio is an Instagram Story, Reel or TikTok photo?
9:16, the full height of a phone screen. The Story or Reel preset saves 1080 × 1920 with Exact preset. We found no official TikTok photo spec when we checked in November 2026, so 9:16 is simply the commonly recommended shape there, set by the Full-screen photo preset. The catch is cropping. A landscape 4:3 shot cut to 9:16 keeps only 42.2%. A 16:9 one keeps 31.6%. Add background with Blurred photo keeps the whole scene instead. Our guide on how to make an Instagram Story collage covers putting several photos into that tall frame.
What ratio works best for a Facebook post?
4:5, by Meta's own advice. The Meta Ads Guide now lists one shape for Facebook Feed images: 4:5 at 1440 × 1800. It allows a 3% tolerance on the ratio, so a file a few pixels off still passes. Its Facebook video feeds spec still takes 1.91:1 to 4:5, with 1440 × 1440 for a square. Here, the Feed portrait and Feed square presets give those exact sizes with Exact preset. Feed landscape and Story set the shape only and keep your photo's own resolution.
Which photo shape shows in full on X?
Anything between 2:1 and 3:4. X's help page on posting photos says a single photo inside that range displays in full. It promises nothing for shapes beyond it, so stay inside. One post holds up to 4 photos. The presets "Post, widest shown in full" and "Post, tallest shown in full" set those two limits for you, while "Post, landscape" gives 16:9. None of the three carries a pixel size, so the download keeps your photo's own detail. A 4:3 phone shot already sits inside the range and needs nothing.
What aspect ratio does LinkedIn use for image posts?
Anything from 3:1 to 4:5. LinkedIn centres and crops an image outside that range. Its help page sets a minimum of 552 × 276 pixels, recommends 1080 pixels wide and caps uploads at 5 MB. Multi-photo posts hold up to 20 images and render at 4:5 at most. Here, the LinkedIn presets give Portrait post at 1080 × 1350, Square post at 1080 × 1080 and Widest post at 3:1. Go 4:5 when you want the post to take up the most room in the feed.
What is the best aspect ratio for a Pinterest pin?
2:3. Pinterest recommends 1000 × 1500 pixels for a standard pin. It warns that pins taller than that might get cut off in the feed, so a very long infographic can lose its bottom. An upright 3:4 phone photo crops to 2:3 keeping 88.9%, a small price. A landscape 4:3 shot keeps only 50.0%. For that one, Add background with a Colour fill usually works better and leaves room for a headline. The Standard Pin preset sets both the shape and the exact size.
What shapes does YouTube want for thumbnails, Shorts and channel art?
Video thumbnails want 16:9, recommended at 3840 × 2160. Shorts thumbnails want 9:16, at 2160 × 3840. YouTube Help sets a floor of 640 pixels wide for video thumbnails and 640 tall for Shorts. Both take JPG or PNG. A video thumbnail can be up to 2 MB from a phone. From a computer, either kind can be up to 50 MB. The channel banner is 16:9 as well, recommended at 2560 × 1440, with a minimum of 2048 × 1152 and a limit of 6 MB. Keep text inside the 1235 × 338 safe area in the middle. All three sizes are presets here.
Can one photo work as both a square post and a Story?
Yes, make two copies. Use Photo only at 1:1 for the post, download, then switch to 9:16 with Add background and Blurred photo for the Story. The ratio goes into each file name, so the two never overwrite each other. For a collage that has to live in both places, CollagePhotoApp, our free app for iOS and Android, offers six canvas sizes: 1:1, 9:16, 4:3, 3:4, 5:4 and 16:9. Switch a square post to a Story and the design refits itself instead of chopping the edges off.
What aspect ratio is a 4×6 print?
2:3 upright and 3:2 held landscape. That is the frame most DSLR and mirrorless cameras shoot, so their photos print at 4×6 keeping 100.0%. Phone photos fit less neatly. An upright 3:4 phone shot keeps 88.9% at 4×6, which means 11.1% comes off the left and right edges. Crop it yourself and you choose what goes: a 3024 × 4032 photo comes out 2688 × 4032. Would you rather keep everything? Add background with White leaves thin margins and gives the lab nothing to trim. The preset is called 4×6 in (10×15 cm).
What aspect ratios are 5×7, 8×10 and A4 prints?
5×7 is 5:7, 8×10 is 4:5 and A4 is 1:1.414, the square root of 2. All three sit closer to square than a 2:3 camera frame, which is why camera photos lose more at 5×7 and 8×10 than phone photos do. From an upright 3:4 phone shot, 5×7 keeps 95.2%, 8×10 keeps 93.8% and A4 keeps 94.3%. From a 2:3 camera shot, 8×10 keeps only 83.3%. At A4 the two tie. A4 belongs to the ISO 216 series, where halving a sheet keeps the same shape, so the A4 button fits A3 and A5 too. US Letter works out at 17:22.
Why do phone cameras take 4:3 photos?
Because 4:3 is usually the whole frame the sensor captures. Every other shape gets cut from it. Google's Pixel Camera Help gives the game away in its labels: the ratio setting offers Full image (4:3) and Wide crop (16:9). The iPhone Camera offers 1:1, 4:3 and 16:9 under Aspect. A 12.2 megapixel phone photo at 4:3 measures 4032 × 3024. The shape is older than phones. Early digital cameras chose 4:3 to match the computer monitors of their day. Shoot 4:3 and crop later, since that keeps every option open.
Why are DSLR and mirrorless photos 3:2?
Because they inherited the shape of 35 mm film. A classic 35 mm frame measures 36 × 24 mm, a 3:2 rectangle. Full-frame sensors keep exactly that size. Camera makers built DSLRs to match the film SLRs before them. The shape stuck. A 24 megapixel file of 6000 × 4000 is 3:2. Micro Four Thirds bodies break the pattern at 4:3. The longer frame costs more in a crop. A 3:2 landscape keeps 53.3% at 4:5, against 60.0% for a 4:3 phone shot.
What is the difference between 16:9, 16:10 and 21:9 screens?
16:9 is the international standard for HD television, the shape of 1920 × 1080 and 3840 × 2160. 16:10, which the readout writes as 8:5, is a little taller and turns up mostly on computer displays and tablets, as in 1920 × 1200. 21:9 is a marketing name. Wikipedia's 21:9 article explains that most such screens are really 64:27, about 2.37:1, as on 2560 × 1080. A 3440 × 1440 monitor is 43:18, wider still. The 21:9 button here is exact, about 2.33:1. For a wallpaper that fills an ultrawide edge to edge, type 64:27 or 43:18 into Custom ratio.
How do I give a photo a cinematic widescreen look?
Type 2.39:1 into Custom ratio and crop. That is the shape of today's anamorphic widescreen cinema releases. The older flat widescreen standard, 1.85:1, dates from May 1953 and types just as easily as 1.85. A 4K frame of 3840 × 2160 cropped to 2.39:1 becomes 3840 × 1607, keeping 74.4%. Turn on Show grid and set the horizon on a third line. Want black bars too? Open the download again, pick 16:9 and choose Add background with Black. That letterboxes the strip inside a normal widescreen frame, the way a film looks on a TV.
Can I give a whole folder of photos the same aspect ratio?
Yes, up to 50 photos in one go. Drop them all in, leave Changes Apply To on All images and set the ratio and the method once. The download button then counts what you loaded. With 8 photos it reads Download 8 Images as ZIP. The ZIP lands as Image Aspect Ratio Changer - CollagePhotoApp.com.zip. The tool works through one photo at a time and lets go of each before starting the next, so a phone never holds the whole set in memory at once. ↺ Reset and start again clears the slate for the next batch.
Does every photo in a batch get cropped from the middle?
No. Every photo keeps its own position and zoom, so the whole batch can share one ratio while each subject stays in frame. Everything starts centred. Step through the batch and drag the window on the shots where someone stands off to one side. One image needs a different ratio? Set Changes Apply To to Only this image and change it alone. Copy to all goes the other way and hands the current image's settings to every other one.
How are the downloaded files named?
Each file keeps its original name, then adds the ratio and our suffix. beach.jpg at 4:5 saves as beach-4x5-aspect-ratio-changer-collagephotoapp.com.jpg. The colon becomes an x, because Windows refuses colons in file names. Decimals survive, so 1.91:1 turns into 1.91x1. If two photos in a batch share a name, the second one gets -2 before the ratio, as in beach-2-4x5-aspect-ratio-changer-collagephotoapp.com.jpg. Case doesn't count, so Beach.jpg and beach.JPG clash too. Nothing in the ZIP overwrites anything else. Our name appears in the file name and nowhere in the picture.
Can I copy the result to the clipboard instead of downloading it?
Yes. Copy Image puts a PNG of the result on your clipboard, ready to paste into a chat, an email, a slide or a design app. In a batch the button reads Copy This Image and copies the photo on screen. From an animated GIF it copies the first frame only. Browsers decide whether a page may write images to the clipboard, so the button works where yours allows it. Where it refuses, Download still works. PNG means the copy loses nothing, transparent areas included.
Which file types go in and which come out?
Five formats open in any browser: JPG, PNG, WebP, GIF and BMP. Safari adds HEIC. So do Chrome, Edge and Firefox on an iPhone or iPad. On the way out, Save As offers JPG, PNG or WebP, plus Same as original, which hands back the format you started with whenever a browser can write it. A JPG returns as a JPG. A WebP returns as a WebP. A GIF returns as a GIF, animation and all. BMP is the first exception, saved as PNG with every pixel intact in a fraction of the bytes. HEIC is the second, saved as JPG. If a browser cannot write WebP, the tool saves a PNG, names it .png and tells you.
Does this tool accept iPhone HEIC files?
Yes, in Safari, which reads HEIC natively on iPhone, iPad and Mac. On an iPhone or iPad, Chrome, Edge and Firefox open it too, because there they run on Safari's engine. Chrome, Edge, Firefox and Samsung Internet on Windows, Mac and Android cannot decode HEIC, so the file will not load in them. On a Mac, switch to Safari. On a Windows PC or an Android phone, export the photo as JPG first or open this page on the iPhone that took it. With Same as original the reshaped copy saves as JPG. No browser can save HEIC. JPG opens everywhere.
Will an animated GIF keep moving after its shape changes?
Yes. Every frame gets the same crop, fit or stretch and the timing between frames stays as it was, so the loop plays exactly as before in its new shape. Leave Save As on Same as original, the setting that writes a GIF back out. Blurred photo works here too. Its backdrop moves along with the clip. One ceiling applies: the frames of a single file can add up to 400 million pixels, counted at the larger of the old and the new frame size. Cropped, a 400 × 400 clip still gets 2,500 frames. Fitted to 9:16 it gets 1,406, still far more than a reaction clip needs.
Who can see the photos I reshape here?
Only you. Everything is processed here itself, nothing is uploaded to our servers. The page reads each photo from your device, reshapes it in memory and hands the file straight back to your downloads folder. We hold no copy, so there is nothing on our side to guard or lose. You can check this yourself. Open the developer tools in your browser, watch the network tab while a batch saves and you will see no picture leave. Close the tab and the photos are gone from the page.
Will the reshaped photo still reveal where it was taken?
No. The download carries no GPS location and no EXIF camera data, because the tool writes a brand new file from the pixels rather than editing your original. Nothing about where, when or with what you shot it comes along. One thing does carry over in spirit: orientation. The tool applies the EXIF orientation before any reshaping, so an upright phone shot stays upright and needs no tag to show the right way round. Your original keeps all of its metadata, untouched, on your device.
Does the aspect ratio changer cost anything or add a watermark?
No on both counts. Every ratio, fill, preset and batch is free, with no sign-up, no watermark and no cap on how many images you reshape in a day. Two practical limits remain: 50 images per batch and the memory of your device. The pictures carry no logo, badge or stamp. Our name shows up in the file name only. A rename wipes even that. Your own device does the work, so one more image costs us nothing to serve.
Can I change a photo's aspect ratio on my phone?
Yes, in the browser on an iPhone or an Android phone, with nothing to install. Tap to add photos from your gallery, then drag the bright window with a fingertip to frame the crop. The buttons, presets and sliders match the desktop page. Copy Image is handy on a phone. Copy the result and paste it straight into a chat or a post where your browser allows it. Very large results may save smaller on an iPhone, because Safari limits how many pixels one image may hold.
Why did my result save smaller than expected on an iPhone?
Safari caps how many pixels one image may hold. Add background can grow a frame past that cap. iPhones on iOS 17 or earlier stop at 16,777,216 pixels (16.8 MP). iOS 18 raised that limit. There the tool works up to 33.6 MP to stay inside the phone's memory. Everywhere else the tool allows 50 MP. Fit a 12.2 MP photo to 9:16 and the frame reaches 4032 × 7168, which is 28.9 MP. iOS 18 saves that in full. iOS 17 scales it down to fit. The editor tells you when that happens. For every pixel, finish the job on a computer.
Why is there no AI option to extend the background?
Because inventing new scenery takes either a server or a model several gigabytes in size. A server means your photo leaves your device, which this page never allows. A multi-gigabyte download is no way to open a free web tool on a phone. AI fill has a second problem: whatever it paints at the edges is a guess, not your photo. It can sprout an extra hand or a sixth window. Blurred photo and Mirror extend the edges honestly, from pixels you actually took.
How do I straighten a tilted photo before changing its ratio?
Use Rotate Image first, since this tool changes the shape and leaves the angle alone. Level the horizon there with its Crop to fill, then bring the download here and pick your ratio. Order matters. Straighten after cropping and the turn trims the edges again, eating into a frame you had just got right. A phone photo that other sites show sideways needs no fix first. This tool reads its orientation tag and stands it upright before any reshaping.
How do I turn a wide panorama into Instagram carousel slides?
Use the Instagram Carousel Splitter rather than a ratio change. Cropping a 16:9 panorama to 4:5 keeps only 45.0% of it. A true panorama is wider still. The splitter cuts the full width into slides that join edge to edge as people swipe. This page still has a job before that. Crop the panorama to an exact multiple of the slide shape so nothing is left over: 3:1 for 3 square slides, 12:5 for 3 slides at 4:5. Type either into Custom ratio.