Compress an image to 20 KB
20 KB is a signature-sized allowance. It is reachable, but only for the right kind of picture.
Where 20 KB comes from
- Examination forms asking for a scanned signature, commonly between 10 KB and 20 KB.
- Older government portals with separate, very small allowances for a photograph and a signature.
- Forum and profile avatars with a hard size cap.
What actually fits in 20 KB
Worked out from what this tool produces, not from a rule of thumb. Where a row says no, it says what to do instead.
| What you have | Fits in 20 KB? | What it takes |
|---|---|---|
| A signature on white paper | Comfortably | It is mostly white — the format compresses that almost to nothing |
| A passport-style headshot | Yes | Around 300–400px wide; fine on a form, not for printing |
| A photo of a full page of text | No | Readable text needs width, and 20 KB does not buy enough of it |
| A detailed colour photograph | It will fit, badly | Expect visible blocking. If the detail matters, this is the wrong limit to accept |
A signature should be scanned or photographed against plain white and cropped tightly before compressing. Cropping is free: half the picture removed is half the bytes, with no loss at all in what is left.
The search stops narrowing at 480px wide. Below that a photograph of anything with writing on it stops being readable, and a file that passes the upload but cannot be read has not solved anything.
Questions
- My signature file is 2 MB. Is 20 KB really possible?
- Yes, easily, and it will still look clean. A signature is a few dark strokes on a white field, which is the easiest thing there is to compress — the 2 MB is the camera, not the signature.
- The form wants 10–20 KB, not just under 20 KB. Can I hit a range?
- Set the target to the top of the range. The search finds the highest quality that fits under it, so the result lands as close to the ceiling as the encoder allows rather than far below it.
A different limit?
Every one of these opens the same tool with a different number in the box. If the limit you were given is not here, open Compress Image and type it in.