Compress Image to 20 KB

Made for signatures, thumb impressions and small photos on application forms. Add the image and download a JPG under 20 KB, readable and checked to the byte.

Maximum file size

Every file comes out at 20,000 bytes or less, so it passes forms that count 1 KB as 1,000 or as 1,024 bytes.

Minimum size (optional, some forms set one)

or drop them here, or paste with Ctrl+V. JPG, PNG, WebP, up to 20 at once. They never leave your device.

How it works

Pick the size
20 KB is selected. Choose another preset or type your own limit if your form asks for something else.
Add your images
Choose files, drop them on the box or paste a screenshot. Up to 20 at once, nothing is uploaded.
Download
Each file is checked against the limit and named after it, like photo-50kb.jpg. Several files come as one ZIP.

What usually has to be under 20 KB

Twenty kilobytes is the classic limit for a scanned signature. Many recruitment, exam and admission portals ask for a signature of about 10 to 20 KB, sometimes a left thumb impression or a handwritten declaration in the same range, and some ask for the photo too. The exact limits change from one notification to the next, so check yours before you upload.

How to get a clean signature under 20 KB

Sign with a black or dark blue pen on plain white paper. Faint ink means a grey, noisy scan.
Photograph it in daylight, flat, with no shadow from your phone.
Crop tight around the signature before you add it here. A signature is wide and short; empty paper around it costs bytes and makes the ink smaller once the form displays it.
If the form asks for a minimum too (often 10 KB), type it in the minimum box: the tool will warn you if the result falls below it.

How many pixels fit in 20 KB

At JPEG quality 80, 20 KB holds a photo about 330 to 470 pixels on its long side. A signature on white paper is mostly empty and fits far more. Here is how 20 KB compares with the other common limits:

Largest long side of a photo that fits each size at JPEG quality 80
Limit	Long side at good quality
20 KB	330 – 470 px
50 KB	560 – 770 px
100 KB	860 – 1,140 px
200 KB	1,170 – 1,600 px

For reference: measured on five real photos (landscapes, a workshop interior, a screenshot) at JPEG quality 80. A plain background fits more pixels, a busy one fewer. The tool itself keeps the full size whenever a quality of at least 50 fits, and only then shrinks.

Questions

How do I compress a signature to 20 KB?

Crop the photo of your signature tightly, add it here with 20 KB selected, and download the JPG. The tool keeps the highest quality that fits, so the strokes stay sharp. The result line shows the exact size, like 18.7 KB.

My signature is a PNG with a transparent background. Is that a problem?

No. Transparent areas are filled with white before the JPG is made, which is what forms expect. Without that, many tools turn the background black.

The form needs between 10 KB and 20 KB. Can I set both?

Yes. Keep 20 KB as the maximum and type 10 in the minimum box. The tool aims just under 20 KB, so you normally land well inside the range, and you get a warning if a very simple image stays under 10 KB even at top quality.

Why did my photo get smaller in pixels?

At 20 KB a large phone photo cannot keep all its pixels, even at low quality. Rather than hand you a blurry, blocky file, the tool scales it down until a decent quality fits, and tells you the new dimensions.

Is 1 KB 1,000 or 1,024 bytes?

Both are in use, and forms rarely say which. That's why the tool aims under the stricter one: a 50 KB file here is at most 50,000 bytes, which is also under 51,200 bytes. The exact byte count is shown next to every result.

Are my photos uploaded anywhere?

No. The page compresses them inside your browser with the canvas built into it. Your files never reach a server, so ID cards, signatures and certificates stay on your device. You can even switch off your connection once the page has loaded.