Compress Image to 20KB
Compress an image to 20 KB in one step: drop a photo or scanned signature below and the 20 KB target is already set. The compressor finds the best quality that fits under the limit, right in your browser, with nothing uploaded and no signup.
Drag and drop an image here, paste from your clipboard, or
JPG, PNG, WebP, HEIC, AVIF, and most other image formats — up to 25 MB. Nothing is uploaded.
Pick the limit an upload form gives you, or choose "No target" and use the quality slider. 1 KB here is 1,000 bytes, so the result passes forms that count a kilobyte either way.
Lower quality means a smaller file; 75–85% is usually invisible on photos.
Shrinks the long edge — useful for social media, email, and web uploads.
Where 20 KB limits come from
A 20 KB cap is the tightest limit in common use, and it almost always means one of two things: a scanned signature or a small photo thumbnail on a government, exam, or job application form. Portals set it low because they store millions of these, and at the size they display a signature (often around 140 × 60 pixels) 20 KB is plenty. A phone camera, though, produces files of 3 to 5 MB, so getting there means discarding more than 99% of the data. Doing that well depends on what you discard.
How to resize a signature to 20 KB
Signatures should be the easiest images to shrink: dark ink on white paper, almost no detail. In practice a phone photo of a signature carries grey paper texture, shadow, and sensor noise, and a JPEG encoder spends most of its bytes describing exactly that. Three steps fix it:
- Sign on plain white paper with a dark pen, and photograph it in even daylight, flat, with no shadow from your phone.
- Crop to the ink with the image cropper. Every row of blank paper you remove is data the encoder no longer has to store.
- Compress here with the 20 KB target. A clean, cropped signature typically lands well under the limit at a quality high enough that the strokes stay sharp.
Getting a photo under 20 KB without blocky artifacts
For a photo, the order matters more than any setting. The compressor first searches JPEG quality for the highest value that fits. If even its lowest quality is still too big, it reduces the pixel dimensions and searches again. That second step is what keeps a 20 KB face recognisable: a 250-pixel-wide photo at good quality looks far better than a 4000-pixel photo crushed until it falls apart into 8 × 8 blocks. If the form specifies dimensions, set them first with the cropper so the compressor is working with the final size.
Why the result shows exact bytes
"20 KB" means 20,000 bytes to some forms and 20,480 to others. This tool always targets the smaller number and shows the result in exact bytes, so you can see it will pass either check before you download. Keep the output as JPG unless the form asks otherwise. It is the format every portal accepts, and PNG has no quality setting to trade for size, so it has to shrink much further to reach the same limit. For a larger limit, use the 50 KB compressor, or the main image compressor for any size. The guide to reducing image size in KB covers each limit in more depth.
Frequently asked questions
How do I compress an image to 20 KB?
Drop the image into the box above. The 20 KB target is already selected, so the compressor searches for the highest quality that fits under 20,000 bytes and shrinks the pixel dimensions only if quality alone cannot get there. Check the exact byte count shown under the result, then download.
How do I resize a signature to 20 KB?
Crop the photo of your signature tightly to the ink first, using the image cropper, so no blank paper is left around it. Then compress it here with the 20 KB target. A tightly cropped signature usually lands well under 20 KB with the ink still crisp, because there is so little detail to store.
Why does the form still say my 20 KB file is too large?
Some forms count a kilobyte as 1,024 bytes and some as 1,000. This tool always targets 1,000-byte kilobytes, so a result shown as under 20,000 bytes passes either check. If a form still rejects it, it usually has a separate pixel-dimension rule, or it rejects the format: save as JPG, which every form accepts.
Will a 20 KB photo look blurry?
At full phone resolution, yes, because 20 KB cannot describe 12 million pixels. At the size forms actually display, typically 150 to 300 pixels wide, a 20 KB JPG looks clean. That is why the compressor reduces dimensions when needed, rather than crushing quality until the image breaks into blocks.
Is my signature or photo uploaded anywhere?
No. The image is read and compressed by your own browser, and it is never sent to a server. That matters for a signature in particular, since it is exactly what someone would need to forge one.
Related reading
- How to Reduce Image Size in KB (and Hit an Upload Limit First Try)
Crop, resize, then compress, in that order. Plus why a 20 KB file can still be "too large", and how target-size compression really works.