Compress Image to 20 KB
Get any photo under 20 KB automatically, at the best quality that fits.
20 KB is the limit online application portals love for signature scans and thumbnail photos — government exams, university admissions, recruitment sites. A phone photo of a signature is usually 2–4 MB, a hundred times too big.
At this size something has to give, so the order matters: quality is lowered first, and pixels only go when quality alone can’t reach the limit. A signature survives this well because it is dark ink on a flat background — mostly empty space.
Crop tightly around the signature before compressing. Every millimetre of blank paper you leave in costs bytes you’d rather spend on the ink.
How to use it
- Crop the image to just the signature or face first (our crop tool does it in seconds).
- Drop it here — the 20 KB target is already set.
- Check the preview is still legible, then download.
Frequently asked questions
The form also asks for exact pixel dimensions. What do I do?
Resize first to the dimensions it asks for (often something like 140 × 60 for signatures), then compress. Doing it in that order means the size limit is met at the dimensions the form checks.
Why did my image get smaller in pixels?
Because a large photo can’t fit in 20 KB at any decent quality. Rather than turning it into blocky mush, the tool reduces the dimensions until it fits at a quality you can still read.
Should a signature be JPG or PNG?
Whatever the form accepts; most want JPG. If PNG is allowed, it’s often smaller for pure black-on-white signatures, because a signature has so few colours.
The portal still says my file is too big.
Files here are checked against 20,000 bytes, which is stricter than the 20,480 some sites use, so the size itself shouldn’t be the problem. Check the format and pixel dimensions the portal requires — those rejections are often reported as "invalid file".
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