How to compress image to 20KB
20 KB is tight — about the size of a small thumbnail. This tool finds the largest, clearest JPG that fits under 20 KB, resizing only as much as it has to, and shows the exact result before you download.
- Drop, paste or choose your image (JPG, PNG, WebP, GIF, BMP or AVIF). A sample photo is loaded so you can try it first.
- The target is preset to 20 KB. Change it, or pick another preset, if your form asks for something different.
- Optionally choose an output format and a maximum width or height.
- Check the side-by-side preview and the exact byte count, then click Download.
How the compressor hits an exact size
The tool decodes your image in the browser, then re-encodes it with the browser's own JPEG, WebP or PNG encoder. For JPEG and WebP it runs a binary search on the quality setting — usually 6 to 10 test encodes — and keeps the highest quality whose file is at or under your target. If even a low quality (40%) is still too large, it reduces the pixel dimensions by the amount the byte count suggests, then searches quality again, so you get the largest picture that fits rather than a blocky one. PNG is lossless, so for PNG only the dimensions change. If your file is already under the target and you keep the same format, the original is returned untouched.
Everything happens on your device with the Canvas API; nothing is uploaded, and the re-encoded file does not carry the original EXIF metadata (camera, GPS).
Frequently asked questions
Can any photo fit in 20 KB?
Yes, but detailed photos will be resized — typically to roughly 300–600 px on the long side, depending on detail. Simple images like signatures and logos can stay much larger.
What dimensions should I use for a 20 KB photo?
If the form specifies dimensions, enter them under Dimensions — that is the best way to keep it sharp. Otherwise let the tool choose the largest size that fits.
Why not use PNG for a 20 KB limit?
PNG is lossless, so photos in PNG are many times larger than JPEG. Use PNG at 20 KB only for simple black-and-white signatures or icons.
Are my images uploaded to a server?
No. Compression runs entirely in your browser using the Canvas API. The image never leaves your device, which also makes it safe for ID photos and signatures.
Is it free?
Yes. Compressing one image at a time is free with no signup and no watermark. Gridloom Pro adds batch compression of many images with a single ZIP download.