Compress an image to 20 KB
Signature and photo uploads on exam and government forms are often limited to 20 KB. Get there in one step, privately.
Files never leave your deviceNeed more settings? Open the full Compress Image tool.
How to compress an image to 20 KB
- Drop your photo or signature image onto the box above.
- Target size is set to 20 KB, with JPG as the output format.
- Press Compress and wait a few seconds while the best quality is found.
- Check the size and pixel dimensions in the result line, then download.
Made for signatures and form photos
A 20 KB limit is common for the signature and photograph uploads on exam, recruitment and government application forms. It is small, so preparing the image well before compressing makes a big difference.
For a signature:
- sign in dark ink on plain white paper;
- photograph or scan it in good light, without shadows;
- crop tightly around the signature so there is little empty paper;
- then compress here.
For a photo:
- crop to the required shape (often passport style);
- resize to the requested pixel size, for example 200 × 230;
- then compress here.
What the tool does
It first tries high quality, then searches for the highest JPG quality whose file is at most 20 KB. If the image is large, even low quality can be too big, so it then reduces the dimensions in steps until the file fits. You get the sharpest result the limit allows, along with a note of the final size.
If a form asks for a range, such as 10 to 20 KB, and your result is below the minimum, raise it with the main image compressor by choosing a higher quality, or start from a larger image.
Why use a browser tool for this?
Signatures and ID photos are exactly what you should not upload to unknown websites. Here, compression happens on your own device using WebAssembly, so the image is never sent anywhere. Other limits are one click away: compress to 50 KB and compress to 100 KB.
Frequently asked questions
Can a photo really fit in 20 KB?
Yes, at small dimensions. A passport-style photo of around 200 × 230 pixels looks fine at 20 KB. The tool scales larger images down automatically until they fit.
What is the best way to compress a signature to 20 KB?
Crop tightly around the signature first so there is little empty paper, then compress. A clean, well-lit scan on white paper compresses far better than a shadowy phone photo.
The form says 10 to 20 KB. What if my file comes out below 10 KB?
Use the main compressor with a higher quality setting, or resize to slightly larger dimensions, to bring the size up into the accepted range.
Are my files uploaded anywhere? How can I check?
No. The image compressor runs entirely in your browser using JavaScript and WebAssembly, so your files never leave your device. You can verify it: open your browser's DevTools (F12, or Cmd+Option+I on a Mac), switch to the Network tab, tick "Preserve log", clear the list and process a file. You will only see requests for this site's own static files, never one that carries your data. You can also turn on "Offline" in the Network tab (or disconnect from the internet) once the page has loaded, and the tool keeps working.
Does it work offline?
Yes. After your first visit a service worker saves the tool to your device, so it opens and works without a connection. Only advertising needs the internet; the processing never does.