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Compress Image to 20 KB
Compress Image to 20 KB Online — Free & Instant
Compress an image to a 20 KB target for signature and form uploads — large photos are scaled down, and the result says so.
About Compress Image to 20 KB
Signature and photo uploads on exam registrations and government portals carry some of the strictest ceilings on the web — often 10 to 20 KB for a signature and 20 to 50 KB for a photo. This tool compresses your image to a 20 KB target right in your browser: encoder quality is binary-searched first, and because 20 KB is genuinely tiny — a full-resolution phone photo cannot get there at any quality — the engine also scales large images down in bounded steps, each between 50% and 90% of the current size and never below 64 px on the longest side. Whenever that happens, the result tells you the new dimensions, so nothing changes silently. Expect a photograph to come out a few hundred pixels on its longest side at this target; a small scan or signature crop may fit with no downscale at all. Opaque images are saved as JPG, images with transparency as WebP so the transparency survives. Nothing is uploaded — which matters for ID photos and signatures — and if re-encoding cannot beat your original, you get the original back unchanged.
Questions
Who needs an image under 20 KB?
Signature uploads on exam registrations and government portals are the classic case — many specify 10–20 KB for signatures and 20–50 KB for photos. Tiny avatar and thumbnail fields on older systems carry limits this small too.
Will a photo survive compression to 20 KB?
Not at full resolution — 20 KB cannot hold a multi-megapixel photo at any quality, so the engine scales large images down and tells you the new dimensions. Expect a few hundred pixels on the longest side, which is usually exactly what fields with this limit want.
Does this tool change my image's dimensions?
Only when it has to. Quality is lowered first at the original dimensions; the image is scaled down in bounded steps — 50% to 90% at a time, never below 64 px on the longest side — only when no quality can reach 20 KB, and the result reports the new size whenever that happens.
What format does the output use?
JPG for opaque images, because it reaches small targets most reliably; images with transparency come out as WebP so the transparency survives.
What if even scaling can't reach 20 KB?
You get the smallest file the engine managed across all of its attempts — and never one larger than your original.
Is my file uploaded to a server?
No. Transmute processes everything locally in your browser using JavaScript and WebAssembly. Your files never leave your device — there is no server, no upload, no cloud processing.