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KBSize

Compress an image to 20 KB

Set to 20 KB already. Choose a photo and it will find the highest quality that still fits under 20 KB, without uploading anything.

Choose an image and it will be compressed here, in this browser. Nothing is uploaded.

Your image is never uploaded. Compression runs in this browser using the canvas API, and there is no server to send it to. This tool is provided free and without warranty — open the result before you submit it anywhere.

What 20 KB actually allows

20 KB is a tight budget — the kind of limit exam boards and government portals set for a passport photo or a signature. Expect to reduce the dimensions as well as the quality; a small, clean image at 400 pixels wide will look far better than a large one crushed to fit.

Nothing is uploaded

The compression happens in your browser. The image is never transmitted, never stored, and disappears when you close the tab — which matters, because files with a size limit attached are usually identity documents.

What fits inside 20 KB

A JPEG spends bytes on detail, so the number of pixels 20 KB can hold depends entirely on how busy the picture is. These are the rough budgets, and they are why a signature can stay large while a photograph of the same size limit has to shrink.

Kind of imagePixels it can affordRoughly, at 4:3
Signature or line drawing409,600about 740 × 560
Passport or ID photo170,667about 480 × 360
Scanned document page102,400about 370 × 280
Detailed photograph62,061about 290 × 220

Estimates from typical JPEG output at everyday quality. A detailed photograph gets about 62,061 pixels to work with at 20 KB — near enough 290 × 220. Anything bigger has to give up either dimensions or detail, and dimensions are almost always the better thing to give up.

Common questions

How do I reduce a photo to 20 KB?

Choose the file on this page. The target is already set to 20 KB, and the tool searches for the best quality that fits, offering to reduce the dimensions if quality alone cannot get there.

Does it work on a phone?

Yes. It runs in the browser on Android and iOS as well as on desktop, and handles HEIC photos from an iPhone.

What image dimensions fit in 20 KB?

Roughly 290 by 220 for a detailed photograph, and much larger — around 740 by 560 — for a signature or other flat image, because a JPEG spends its bytes on detail rather than on area. The tool works out the real numbers for your specific picture instead of guessing.

Why does my file come out at slightly under 20 KB rather than exactly 20 KB?

Because the target is a ceiling, not a goal. The form you are filling in rejects anything over 20 KB, so the tool searches for the highest quality that still lands underneath and stops once it is close, rather than risking an overshoot.

Other size targets