Compress an image to an exact size in KB

Choose a photo, set the size you need, and download a version that is just under it. It runs in your browser, so the file stays on your device.

Quick answer: choose your image, enter the KB limit from your form (for example 50), press compress, then download the result. If a very small limit forces the tool to shrink the pixel dimensions, the result panel shows the new size.

1. Add images
2. Choose settings
3. Download

Choose imagesor drop them here, or paste with Ctrl+V. Up to 40 at once. They stay on your device.

Output format

JPGWebPPNG

How to shrink

Exact size (KB)Quality

Target size (KB)

Resize (optional)

Max width (px)

Max height (px)

Leave blank to keep the original size. Images are scaled to fit and are never enlarged.

Your settingsChanging any option re-compresses your images automatically.

Files processed0

Total saved0 B

Average reduction0%

Original to result-

How the compressor works

A JPEG or WebP file can be made smaller in two ways: store the picture at a lower quality, or store fewer pixels. The tool tries both in a fixed order so you keep as much detail as possible.

1. It first looks for the highest quality setting that keeps the file under your target at the original pixel size. It does this by trying quality levels and narrowing in on the largest one that fits.
2. If even a fairly low quality is still too large, it shrinks the pixel dimensions in steps (for example to 90%, 80% and so on) and repeats the search, stopping at the first size that fits with acceptable quality.
3. If nothing fits, it tells you so and shows the smallest result it could make, rather than silently handing you a broken file.

Because the width and height are scaled together, the shape of your picture never changes. The result panel shows the final size, dimensions and quality so you can judge the trade-off before you download.

Common size limits and what fits

Estimates assume moderate JPEG quality of about 1.2 bits per pixel. Real files vary with how detailed the picture is.

JPG, WebP or PNG?

How to choose a target size

• Use the number on the form, then aim slightly under it. Some systems count 1 KB as 1,000 bytes and others as 1,024.
• Check dimensions as well. Many forms set a minimum width and height. If a very small target forces the tool to shrink the image below that, raise the target or crop closer instead.
• No stated limit? Around 200 to 500 KB keeps most photos looking good and is accepted by most email and messaging services.

Tips for sharper results

1. Crop to what matters first: a face, a signature or the part of a document you need. Fewer pixels of background means more of the file budget for detail.
2. Start from the best original you have. Compressing an already compressed copy loses detail twice.
3. Scan or photograph documents flat and in even light. Shadows and glare add noise that costs bytes and hurts legibility.
4. Use the comparison slider and zoom in on small text or faces before you download.

If the limit is very small, the tool reduces pixel dimensions as well as quality. Check that the form does not also require a minimum width or height.

Uploading a photo for a passport, visa or ID? Crop it to the right dimensions first with the passport and ID photo size tool, then compress it here if the form also sets a KB limit.

What happens to your image

The tool reads your file into your browser's memory, draws it onto a canvas, and encodes new versions there. No part of that is sent to a server, which you can confirm by turning off your internet connection after the page loads: it still works. Closing the tab clears the image. See the privacy policy for details.

Common sizes

Last reviewed 2026-10-21.