How to Compress an Image to 20KB
20KB is smaller than any one-click preset, so the tool has to shrink your photo's dimensions to get there. Here's how to hit it and keep it sharp.
To compress an image to 20KB, open Compress Image, drop your file in, and type 0.02 into the "Target max size in MB" field. 20KB is 0.02MB, so that's the number to enter. The field's up and down arrows only step down to 0.1, but you can type a smaller value directly and the tool honours it — it aims for roughly 20KB and hands you the result.
The catch is what 20KB does to your image, and it's worth knowing before you rely on it: at this size the tool almost always has to shrink your photo's pixel dimensions, not just its quality.
Why 20KB forces your image smaller
When you set a target, the compressor searches for the highest JPG quality that still fits, working down from about 0.92 toward a floor of 0.40. 20KB is small enough that even that floor usually overshoots at full resolution — so once quality bottoms out, the tool starts scaling the pixel dimensions down and retrying, up to eight times, until the file fits. There is no dedicated one-click page for 20KB the way there is for 50KB and larger, and that's the reason: below about 50KB, a photo can't stay full-size, so the honest tool is the general one with a target you set yourself.
In practice that means a multi-megapixel photo comes back only a few hundred pixels wide. A 2000×1500 photo dropped to roughly 330×250 in our tests; a 1600×1200 landed near 344×258. That's thumbnail and avatar territory — fine for a forum icon or a tiny upload slot, but not something you'd print or use full-screen.
Resize and crop first for a sharper result
Since the tool is going to reduce your dimensions anyway, do it yourself first — you'll get a much better 20KB than letting the compressor shrink a huge image only after it has already crushed quality to the floor. Two steps make the difference:
- Resize down first. Use Resize Image to bring the long edge to roughly 400–600px before compressing. Starting from a sensible size lets the compressor spend its tiny budget on quality instead of a frantic downscale.
- Crop out everything you don't need. Every pixel costs bytes at 20KB. Crop Image tightens the frame to the subject — a head-and-shoulders crop survives 20KB far better than a full scene.
A plain, evenly lit background helps too: busy detail forces the compressor to discard more to hit the number. Then run the resized, cropped copy through Compress Image with the 0.02 target.
When 20KB is the wrong target
20KB is an unusually strict limit. Most portals that enforce a cap sit at 50KB, 100KB, or 200KB, where a photo keeps far more of its detail. If your form actually says 50KB, use the dedicated Compress Image to 50KB tool instead of squeezing to 20KB for no reason — and our guide on hitting an exact size covers the 50/100/200KB cases and why resizing first matters at every one of them. Only aim at 20KB if the upload genuinely demands it.
Everything happens on your device
Compression runs in your browser through the Canvas API — your image is re-encoded locally and never uploaded to a server to be shrunk. Since strict size caps like this often apply to ID photos, signatures, and avatars, that matters: the file only leaves your device when you upload it yourself, wherever the limit actually is.
FAQ
Why is my image so small after compressing to 20KB?
Because 20KB can't hold a full-size photo. The tool lowers quality first, and when that isn't enough it scales the pixel dimensions down until the file fits — so a large photo comes back only a few hundred pixels wide. Resizing it yourself first gives you control over that.
Can I compress to 20KB and keep full resolution?
For a photograph, essentially no. There aren't enough bytes at 20KB to hold millions of pixels at usable quality, so something has to give and the tool gives on dimensions. A simple flat graphic can sometimes stay larger; a detailed photo can't.
Is there a one-click 20KB tool?
No. The dedicated presets start at 50KB because below that a photo can't stay full-size. For 20KB, set the target yourself: type 0.02 into the target field on Compress Image.
What about a PNG?
The target field works for PNG too, but it shrinks a PNG by cutting its colour depth before touching dimensions, which can band a photographic image. If a photo won't reach 20KB cleanly as PNG, convert it to JPG first — JPG compresses photographs far more efficiently. Keep your original either way and compress a copy.