Resize an Image Online

1. Set the target first. Type a width and height in pixels, switch to Percent and type a number, or tap a platform size such as Instagram post or YouTube thumbnail. The controls sit above the drop zone so a file lands already configured.
2. Choose the image on your device. Drag it onto the panel or press Choose an image. JPEG, PNG, WebP and AVIF are accepted, up to 20 MB each. Nothing is sent anywhere at this point, or at any other point.
3. Press Resize image. Your device opens the file, scales it and writes the new one, with no transfer to wait for.
4. Download the result. The panel prints the real before and after byte counts and the measured output dimensions, so you can check the result before you keep it.

Use pixels when something else has already decided the number for you: an upload form that wants 1200 px wide, a print template, a thumbnail slot in a theme. Type the number you were given and the guesswork is over.

Use percent when the exact number does not matter but the weight does — a folder of camera photos that all need to be roughly half as big, or a screenshot that is simply too large for the page it is going on. Percent keeps every image proportional to itself instead of forcing a mixed set into one shape.

The aspect ratio is the relationship between the two sides. A 4000×3000 photo is 4:3; halve both numbers and it is still 4:3, which is why it still looks right. Change only one of them and it does not — the picture stretches.

With Keep the aspect ratio ticked, typing a width fills in the matching height for you, and the other way round. Leave one field empty and the tool works the second side out the same way.

Set both sides to numbers that do not match the original ratio — which is what every platform size does — and the image is scaled up until it covers the frame, then the overflow is trimmed evenly from the edges. That is a crop, not a stretch, and it is almost always what you want for a profile picture or a cover image.

Pixel dimensions describe how big the picture is. File size describes how many bytes it takes to store. The two move together, but not one for one: halving both sides quarters the pixel count, and a JPEG usually lands between a fifth and a third of its old weight rather than exactly a quarter, because compression works on detail, not on area alone.

If you have a hard byte limit to hit — a job portal that rejects anything over 200 KB, an email that bounces over 10 MB — resizing is the blunt half of the job and quality is the fine half. Resize first, then compress to the exact number.

Every size below is a chip above the drop zone, so you never have to remember one. The last column says where each number came from: 7 of the 12 are the size the platform’s own help page states, and the rest are the export sizes people have settled on. There is a list of the pages we read further down.

Site icons are the one job this table cannot do in a single pass: a browser tab, an iPhone home screen and an Android install prompt each want a different square, and the sizes come from Microsoft, Apple and Chrome rather than from a platform’s marketing page. The favicon and app icon generator makes all six from one logo, with the document behind each size listed beside it.

A chip that names a size is a claim about somebody else’s product, and a claim like that goes stale without anyone here touching a file. So every one of them was read back against the platform’s own help page, and the sizes nobody publishes are named as conventions instead of being dressed up as rules.

• Instagram post 1080×1080 — Instagram Help Center, checked September 10, 2026
• Instagram portrait 1080×1440 — Instagram Help Center, checked September 10, 2026
• YouTube thumbnail 3840×2160 — YouTube Help, checked September 10, 2026
• LinkedIn post 1200×627 — LinkedIn Help, checked September 10, 2026
• LinkedIn banner 1584×396 — LinkedIn Help, checked September 10, 2026
• Facebook cover 851×315 — Facebook Help Center, checked September 10, 2026
• Pinterest pin 1000×1500 — Pinterest Business Help, checked September 10, 2026

The other 5 — Instagram story, Instagram profile, X post, WhatsApp profile and Discord avatar — have no published size behind them. Instagram documents no story or profile-picture size, X documents a range of accepted shapes rather than a pixel count, and WhatsApp and Discord each document only a floor. Those are the export sizes in common use. They will not be rejected anywhere, but nobody at those companies asked for them.

Two of the twelve moved on this pass. Instagram now keeps a feed photo at a width of 1080 pixels with a height of up to 1440, so the portrait chip is 1080×1440 rather than the 1080×1350 it read for years, and YouTube now recommends a 3840×2160 thumbnail rather than 1280×720. Both of the older sizes still upload without complaint. Neither is what the platform asks for any more.

Switch the panel to the batch mode and the same controls apply to every file you drop in. Each thumbnail carries a tick box, so you choose what actually goes into the run, and a target you pin to a selection overrides the batch default for just those files — useful when half a folder is portrait and half is landscape.

The result is one ZIP, and the panel lists each file with what it weighed before, what it weighs now and the percentage saved, plus the total across the batch. Those numbers are read out of the archive itself rather than estimated.

20 MB per file and 8000 pixels on the longest side. A batch takes 20 images and 80 MB in total. Input formats are JPEG, PNG, WebP and AVIF. One image can be saved as JPEG, PNG, WebP or AVIF; a batch writes JPEG, PNG or WebP only.

All of the work is done by your device. The page carries the image code with it, your file is opened where it already is, and the resized copy is written back on the same machine — nothing about it is transmitted, so there is no wait for an upload on a slow connection and no copy of your photo anywhere else. The output is built from raw pixels, which is why it carries no EXIF or GPS data. There is no account to create and nothing is added to the image.

The one thing that varies is your hardware. Opening a photograph costs several times its file size in memory, so a 48-megapixel image is heavy work for a phone. The panel checks what the browser can spare first, and if a job will not fit it says so and suggests a smaller target instead of losing your file part way through.