About this tool
Re-encode JPG, PNG or WebP images into smaller JPEGs using the mozjpeg encoder compiled to WebAssembly — the same encoder professional tools use, producing noticeably smaller files than the browser's built-in JPEG at the same visual quality. Pick a quality, see the before/after size, and download. Everything runs in your browser; the image is never uploaded.
Frequently asked questions
How is this better than a normal "save as JPEG"?
It uses mozjpeg via WebAssembly, which fits more quality into fewer bytes than the browser's default JPEG encoder — often 20–40% smaller at the same visual quality.
Is my image uploaded to a server?
No. The image is decoded on a canvas and re-encoded by the WASM mozjpeg codec entirely in your browser — nothing leaves your device.