Is 20KB enough for a signature scan?

Yes — signatures are simple black-on-white images that compress very well, so 20KB usually keeps them perfectly readable.

Does it work on my phone?

Yes. It runs in the mobile browser, so you can shrink a photo to 20KB straight from your phone with no app.

What happens if my image is already under 20 KB?

Nothing is re-saved. The tool checks the size first and keeps the original untouched when it already fits, so you do not lose quality by compressing a file that was never over the limit.

Why did the pixel dimensions change?

Quality reduction alone cannot always reach 20 KB, especially with a colour photo. When it runs out of room, the tool reduces width and height in small steps until the file fits, which is why a large photo comes out smaller on screen.

Compress Image to 20KB

Reduce an image to 20KB for signature fields, small icons and restrictive forms.

Target size

Drop an image here or click to choose

processed on your device — never uploaded

Twenty kilobytes is the strictest limit most people ever meet, and it nearly always comes from an application portal: exam registrations in India that want a signature between 10 and 20 KB, government forms with a tiny photo field, older scholarship and licence applications. The field refuses anything larger and rarely explains why. This page starts with 20 KB already set as the target, so you drop the file and get back the largest, cleanest version that fits.

Two things are worth knowing. A scanned or photographed signature is an easy case: mostly white paper and a few dark strokes compress extremely well, and the result stays crisp. A colour photo is harder. To land under 20 KB the tool first lowers the compression quality and then, if that is still not enough, shrinks the pixel dimensions step by step, so a face photo typically comes out a few hundred pixels wide. Fine for a form thumbnail, not for print. If the portal also sets minimum dimensions, check them before compressing.

If your file is already below 20 KB the tool leaves it alone rather than degrading it for no reason. JPG, PNG and WebP are accepted, and the whole process runs in your browser, so a signature you use on legal paperwork never leaves your device.

More sizes & options

Frequently asked questions

Is 20KB enough for a signature scan?: Yes — signatures are simple black-on-white images that compress very well, so 20KB usually keeps them perfectly readable.
Does it work on my phone?: Yes. It runs in the mobile browser, so you can shrink a photo to 20KB straight from your phone with no app.
What happens if my image is already under 20 KB?: Nothing is re-saved. The tool checks the size first and keeps the original untouched when it already fits, so you do not lose quality by compressing a file that was never over the limit.
Why did the pixel dimensions change?: Quality reduction alone cannot always reach 20 KB, especially with a colour photo. When it runs out of room, the tool reduces width and height in small steps until the file fits, which is why a large photo comes out smaller on screen.

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🔒 Your files are processed on your device. This tool runs entirely in your browser — nothing is uploaded.