Compress an image to 20 KB
Drop a photo and get it back just under 20 KB — the size asked for by signature and thumbnail uploads on exam and government portals. Free, and the photo is never uploaded.
Each file lands just under this size.
If quality alone can't reach the size, the image is scaled down until it fits. The new size is shown on the file.
How did this tool do?
About compressing to 20 KB
20 KB is about the tightest limit an online form will ask for. It turns up on signature boxes, thumbnail photos and older government portals built when bandwidth was expensive and every upload counted.
At that size a full-colour photograph will visibly soften — that's unavoidable, and forms that ask for 20 KB generally expect it. A signature on white paper or a black-and-white scan, on the other hand, holds up perfectly well, because there's little colour detail to lose.
Most compressors hand you a quality slider and leave you to save, check the size, and try again. This one runs that loop for you: it encodes at several quality levels, narrows in until the file sits just under 20 KB, and tells you which quality it settled on.
If it still won't fit at a quality you can accept, the image has too many pixels rather than too much quality. A 4000-pixel-wide photo squeezed into 20 KB will look poor whatever you do. Resize it to the dimensions the form asks for first — often around 200 × 230 for photos or 140 × 60 for signatures — and the same 20 KB suddenly buys a much sharper result.
For a signature, sign in black or dark blue ink on plain white paper, photograph it in daylight without a shadow across the page, and crop tightly so the signature fills the frame. A signature that fills the box stays crisp at 20 KB; a small one surrounded by paper wastes most of the budget on white.
Some forms give a range rather than a ceiling, such as 10 to 20 KB, and reject files that are too small as well as too large. The compressor lands just under the number you type, so enter the top of the range. That keeps the most quality and sits comfortably above the minimum.
Where you'll meet it
Signature uploads
Exam and government portals commonly cap signatures between 10 and 20 KB.
Thumbnail photos
Older forms use a small photo box with a limit to match.
Several files, one budget
When a form caps the total of everything you attach.
Other sizes
How to use it
- 01Drop your image, or paste one with Ctrl+V. JPG, PNG, WebP and HEIC all work.
- 02The target is already set to 20 KB — change it if your form asks for something else.
- 03Tap Compress. Quality is lowered step by step, and the photo is scaled down only if that's the only way to reach 20 KB.
- 04Compare the result with the original, then download.
Compressing images, answered
My form says the signature must be 10–20 KB. What should I set?
Set 20 KB, or 19 KB to be safe. The file comes back just under the number you enter, so it lands at the top of the range, where the signature is sharpest. A file is only likely to fall below the minimum if the image is tiny to begin with.
How do I make a photo exactly 20 KB?
Drop it above and tap Compress. The target is already 20 KB, and each file comes back just under that — the quality that was needed is shown on the file, so you can see how hard it had to work.
Will my photo still look good at 20 KB?
It depends on the dimensions. A passport-sized photo at 20 KB looks fine; a full-size camera photo squeezed to 20 KB will soften. Use Compare before downloading, and crop or resize first if you only need part of the image.
What if the form also wants exact dimensions?
Resize first, then compress. The resize tool has presets for passport photos (35 × 45 mm) and common pixel sizes, and compressing afterwards keeps those dimensions unless the size target can't be met any other way.
Why does the form ask for 20 KB?
Upload limits keep storage and bandwidth predictable — 20 KB is a common one for signature and thumbnail uploads on exam and government portals. The limit is about the file size in kilobytes, not how large the photo looks on screen.
Is my photo uploaded anywhere?
No. Compression runs in your browser, so the photo never leaves your device — which matters when you're sending ID documents to a form.