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Resize Image to 20 KB
Resize Image to 20 KB Online — Free & Instant
Get an image under 20 KB: quality drops first, dimensions shrink in bounded steps only when they must — and the result reports the new size.
About Resize Image to 20 KB
To be upfront about what this page does: it runs Transmute's target-size compressor, not a dimension picker. You do not choose output dimensions here — the tool lowers encoder quality first, and scales the image down in bounded steps only when no quality setting can reach 20 KB at the current size. Each step lands between 50% and 90% of the previous dimensions, never below 64 px on the longest side, and whenever a downscale produced the final file, the result says exactly what happened: 'Scaled to width×height to reach the target size.' At a target this small, that disclosure is the rule rather than the exception — a full-resolution photo cannot reach 20 KB at any quality, so expect the output to be a few hundred pixels on its longest side. That is usually exactly what a signature or thumbnail upload field wants. If you need specific pixel dimensions instead of a byte ceiling, use the Image Resizer. Everything runs locally in your browser, and the output is never larger than your original file.
Questions
Does this tool let me choose the output dimensions?
No — this page targets a file size, not a pixel size. If you need exact output dimensions, use the Image Resizer; if you need both, resize there first and then meet the 20 KB ceiling here.
Will my image's dimensions change?
For photos, almost certainly — 20 KB is below what full-resolution images can reach at any quality, so the engine scales them down in bounded steps (50% to 90% at a time, never below 64 px on the longest side) and the result reports the new size whenever it does.
How small will my photo end up?
Typically a few hundred pixels on the longest side — the engine keeps the largest dimensions that still fit under 20 KB. Small images like signature crops may fit with no downscale at all.
Why did I get a WebP file back?
Your image has transparency. Opaque images come out as JPG, which reaches small targets most reliably; transparent ones are saved as WebP so the transparency survives instead of turning black.
Is my file uploaded to a server?
No. Transmute processes everything locally in your browser using JavaScript and WebAssembly. Your files never leave your device — there is no server, no upload, no cloud processing.