20 KB is the limit you meet on exam and recruitment portals for a signature or a passport-style photo, and on some old intranet forms. It is tiny: a phone photo is often 150 to 300 times bigger. No amount of quality tuning gets a 12-megapixel picture there in one piece, so this page starts with a max width of 600 pixels.
For a signature, crop tightly around the ink first and keep the background plain white. White paper compresses to almost nothing, ink strokes cost a little, and the shadows from a phone camera cost a lot. A scanned signature at 400–600 pixels wide usually lands well under 20 KB.
How to compress an image to 20 KB
Add the image
Drop it on the panel, browse, or paste it. The target is already set to 20 KB on this page, and the max width starts at 600 pixels.
Let the search run
The encoder tries qualities from high to low and keeps the best one that lands under 20 KB. If quality alone cannot get there, it reduces the pixel size.
Check, then download
Read the before and after sizes on the result card and drag the comparison handle across a face or some text. If it looks rough, lower the max width and run it again; fewer pixels at a decent quality almost always beat many pixels at a terrible one.
Where a 20 KB limit shows up
Signature uploads
Application forms often want the signature between 10 and 20 KB. Crop to the ink, then compress; a full page photo of the signature will not fit.
Passport-style photos on forms
Some portals ask for a face photo of around 20–50 KB at a fixed size such as 200 × 230 pixels. Resize to the size they state, then let the target finish the job.
Getting a signature or ID photo under 20 KB
Photograph the signature in daylight, on white paper, from straight above. Crop it so the ink fills most of the frame. Then set the max width to whatever the form asks for, or 400 pixels if it does not say.
For a face photo, check whether the form gives pixel dimensions. If it says 200 × 230, crop to that ratio first in any photo editor, then enter 200 as the width here. A face at that size compresses to 20 KB comfortably at quality 70 or above.
Keep JPEG as the output. PNG is lossless and a photo in PNG will not reach 20 KB at a usable size.
Pixel sizes that usually fit 20 KB
| Max width | What to expect |
|---|---|
| 300 px | Easily under 20 KB, good quality |
| 600 px | Usually fits, some softening on busy photos |
| 1000 px | Often needs very low quality; reduce width instead |
20 KB questions
How do I compress a signature to 20 KB?
Crop the photo to the ink, keep the background white, set the max width to about 400 pixels, and leave the target at 20 KB. The result is usually 8–15 KB and still crisp.
The result is above 20 KB. What now?
Lower the max width to 400 or 300 pixels and run it again. At this limit the number of pixels is the main thing you control.
Will the form reject a file that is much smaller than 20 KB?
Some forms also set a minimum, often 10 KB. If yours does, raise the max width a little until the file sits between the two limits.
Is my ID photo uploaded while compressing?
No. The compression runs in this browser tab. The photo only leaves your device when you upload it to the form yourself.