Compress Image to 20KB

20 KB is one of the tightest limits you will ever be asked to hit, and it usually shows up on official upload forms — a scanned signature, a small passport-style photo, or a document thumbnail that has to squeeze under a hard cap. At that size you cannot rely on the quality slider alone; you also have to bring the pixel dimensions down. This page is set up to do exactly that.

The compressor below starts with a low quality and a small max width so you land near 20 KB straight away, then you fine-tune while watching the live size. Everything runs inside your browser, so the signature or ID photo you are shrinking never leaves your device.

Why 20 KB is a special case

Most compression targets — 100 KB, 200 KB, a megabyte — leave plenty of room for a full-resolution photo. 20 KB does not. A modern camera photo straight off a phone is 3–8 MB, which is hundreds of times larger than the target, so simply lowering quality will never get you there on its own. The math forces you to also shrink the image’s dimensions.

That is why this page pre-sets a small max width alongside a low quality. Fewer pixels means far less data to store, and it is the single biggest lever for reaching a tiny file. A signature or a head-and-shoulders photo still looks perfectly clear at 500–600 pixels wide, so you lose almost nothing that matters at the sizes these forms actually display.

Getting a signature or ID photo under 20 KB

Signatures are the easiest thing to fit into 20 KB because they are mostly white space with thin dark strokes, which compresses extremely well. Drop the signature, keep JPG, and a width of 300–500px with 40–50% quality usually lands comfortably under the limit while keeping the strokes crisp.

Small photos take a little more care. If a head-and-shoulders photo will not drop below 20 KB, reduce the max width further (try 500px) before you crush the quality — soft edges from a low width are less noticeable than the blocky artefacts you get from very low quality. Check the preview at full size before downloading so you know exactly how it will look on the form.

Is 20 KB too small to look good?

At 20 KB some fine detail is inevitably lost, but for the places that ask for it — form thumbnails, signature boxes, small ID photos — the image is only ever shown at a small size anyway, so the loss rarely shows. The trick is to spend your kilobytes wisely: keep the dimensions just large enough for the display slot and let quality take the hit.

If your form actually allows a little more, 50 KB gives noticeably cleaner results with room to spare. It is worth reading the instructions carefully — many portals quote a range like "10 KB to 20 KB" or "up to 50 KB", and aiming for the top of the range keeps your photo looking its best.

Related tools & guides

• Compress to 50KB
• Compress to 100KB
• Resize signature for a form
• Image compressor