Optimize images inside your browser. Resize and compress them on your own machine, and export. Nothing is uploaded, and it works offline after the first load.
It is a modern fork of the amazing Squoosh app, which has gone quiet over the last few years. Frisp is carrying it forward on a modern stack, current codebase, with the codecs rebuilt and the app being actively maintained.
The codecs are built from current sources. That closed 14 known CVEs, one of them critical (CVSS 9.8), and made a few of them smaller or faster. Where a fix was security only, the output is identical to before, byte for byte.
The app is built on SvelteKit and Svelte 5 as a static site, a smaller and clearer codebase that is easier to build on. A Playwright suite runs the real production build in Chromium and Safari's engine on every change.
- Add an image by file picker, drag and drop, or paste.
- Encode to WebP, AVIF, JPEG XL, JPEG (MozJPEG), or PNG (OxiPNG).
- Optimize an SVG source to a smaller SVG on a dedicated vector lane.
- Resize, reduce the color palette, and rotate.
- Compare before and after side by side, with zoom, pan, and a draggable split.
- A different format and settings per side, remembered between sessions.
- Installable, runs offline, codecs precached.
There is no upload and no server doing the work. Every step happens in the page, and it keeps running with the network off.
Maintained and ready for everyday single-image and bulk optimization work. Bulk Phase 2 and 2b shipped on 2026-07-03; next bulk work is Phase 3 overrides polish, with multi-format compare after that (roadmap, current state).
Recent Chrome, Edge, Firefox, and Safari. The policy has the version floors.
Node 24.12 or newer and npm 11 or newer (see .nvmrc).
npm install
npm run dev # dev server
npm run build # static production build
npm run check # typecheck, production build, static-output audit
npm test # check, unit tests, Playwright e2edocs/README.md maps everything. Useful starts: overview, how the codecs are built, multithreading, user guide, agent guide.
Frisp exists because of Squoosh from GoogleChromeLabs. They worked out how to do all this in the browser with no server and made it look easy. It continues from there under the same Apache 2.0 license.