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 and WebP 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. These are the dimensions each placement is published at.

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 and WebP; output is JPEG, PNG or WebP.

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.