Compress an image to 20 KB
20 KB is a hard target — this page is built for the signature and photo fields on strict application forms that demand it. Add your image and the tool compresses, then resizes, as far as it has to, and tells you the size it reached.
Everything happens inside this browser tab. Your image is not uploaded to a server and is not stored anywhere — close the tab and it is gone.
Being realistic about 20 KB
20 KB is roughly one five-hundredth of a typical phone photo, so getting there always costs something. The tool first searches for the highest JPEG quality that fits; for a target this small that is rarely enough on its own, so it then reduces the pixel dimensions in 20% steps and searches again until the file complies. The good news is that the fields demanding 20 KB — scanned signatures, thumbnail photos on government and exam forms — are displayed tiny, so a small, plain image is exactly what the other side expects.
Questions about the 20 KB limit
Which forms ask for files under 20 KB?
Mostly government and examination portals — competitive exam registrations, visa and licence applications, and bank or SIM onboarding forms in some countries. The strictest fields are usually for a scanned signature, where 10–20 KB caps are standard, with the accompanying photo field allowed slightly more. These systems check the byte count exactly and reject anything over with little explanation.
How do I keep a signature legible at 20 KB?
Start from the best possible source: sign with a dark pen on plain white paper, photograph it straight-on in good light, and crop hard so the signature fills the frame with almost no background. A tight crop of dark ink on white compresses extremely well, and 20 KB is then plenty. What ruins signature scans is shadowy, off-white backgrounds and loose framing — the compressor spends the whole byte budget describing paper texture instead of ink.
Why did my image come back smaller on screen too?
Because quality reduction alone could not reach 20 KB, so the tool also had to shrink the dimensions. There is a floor on how few bytes can describe a given number of pixels; past it, the only honest move is fewer pixels. For a signature or thumbnail photo this is fine — the form displays it at a small size anyway. If the result line says the image is still over 20 KB even at the smallest size, the source is too complex; crop it tighter and try again.
Is there a minimum size I should worry about too?
Some forms specify a range, such as 10–20 KB, and reject files that are too small as well as too large. This tool aims just under the 20 KB line, which lands inside every common range. If a result somehow comes back below a stated minimum, add a little more of the image (a looser crop) so there is more detail to encode, and run it again.
Can any image reach 20 KB?
Almost any, because the tool will resize as far as roughly one-fiftieth of the original dimensions before giving up. What cannot survive the trip is fine detail — a full landscape photo squeezed to 20 KB becomes a small, soft thumbnail. That is not a defect of the tool; it is what 20 KB means. Use this preset for the strict form that demands it, and the 100 KB preset when the limit is looser.