Cutout

Background remover. For free!

Open the app or install it for macOS or Windows.

Cutout removes the background from a photo directly in your browser. There is no login, no subscription, no credits and no watermark, and nothing you have to install. Your image never leaves your device: the models are downloaded once and run locally. A desktop app is there if you want it faster.

Features

• Automatic background removal on open, for photos and illustrations, on any colour of backdrop
• Smart Brush: brush over an object to erase or restore it along its edges
• Manual erase/restore brush and lasso selection
• Undo/redo, zoom and pan, hold-to-compare with the original
• Transparent, solid-colour or photo backgrounds
• Full-resolution PNG (with transparency), WebP or JPG download
• Works on desktop and mobile
• Optional desktop app for macOS and Windows, several times faster

The desktop app

desktop/ wraps the same interface in Electron and swaps the WebAssembly background remover for the native ONNX Runtime build, which is about eight times faster. Everything else, including the Smart Brush, is the code that runs on the web.

Where automatic removal runs	Time per image
Browser, WebAssembly, one thread	about 6.4 seconds
Desktop app, native	about 0.7 seconds

Measured on an Apple silicon laptop, so treat them as a guide rather than a promise.

All the models are bundled into the installer, so the whole app works with no network at all, including the Smart Brush.

To run it from a checkout:

npm ci && npm run build:desktop-ui
cd desktop && npm ci && node scripts/fetch-model.mjs && npm start

npx electron-builder --mac or --win produces the installers. .github/workflows/release.yml does that on every v* tag and attaches them to the release. Those CI builds are not signed, so macOS and Windows both warn on first launch.

A Mac with a Developer ID Application certificate in its keychain signs the app and the DMG with the hardened runtime automatically. To notarize, store the credentials once and submit the DMG:

xcrun notarytool store-credentials cutout --apple-id <email> --team-id <team>
xcrun notarytool submit release/Cutout-mac-universal.dmg --keychain-profile cutout --wait
xcrun stapler staple release/Cutout-mac-universal.dmg

Hosting

The live site is a GitHub Pages project site, built and deployed by .github/workflows/deploy.yml on every push to main. npm run build:pages produces that static export; npm run build produces the server-rendered Cloudflare Workers build instead, which adds the cross-origin isolation headers that Pages cannot set.

Development

Requires Node.js 22.13 or newer.

npm install
npm run dev

npm run build produces the production bundle and npm start serves it; npm run lint runs oxlint. npm install also runs scripts/prepare-ort.mjs, which copies the ONNX Runtime WebAssembly binaries into public/ort.

How it works

• lib/engine/worker.ts runs the models in a Web Worker so the interface stays responsive.
• lib/mask/ holds the alpha-mask primitives (brush, lasso, model-mask application), a memory-bounded undo history, the backdrop measurement that refines automatic results (separate.ts) and the checks that decide when to ask for a second opinion (quality.ts).
• components/editor/Editor.tsx is the editor: canvas rendering, pointer/touch handling, tools and export.

The original pixels are never modified. Every tool edits a separate alpha mask, and the download composites the two at full resolution.

See docs/MODELS.md for the models, their licenses, how automatic removal combines a model with measuring plain backdrops, and the benchmark in bench/ that tests it.

Limits

• Images larger than 25 MB are rejected. Very large images are reduced to 24 megapixels (12 on phones) to fit in browser memory; the editor says so.
• The first run downloads the model weights, about 44 MB for automatic removal and 40 MB more the first time you use the Smart Brush.
• Automatic removal takes a few seconds per image on a current laptop, and longer on phones or in a backgrounded tab. docs/MODELS.md explains why it runs on one thread in Chrome.
• The app must keep the cross-origin isolation headers in next.config.ts and public/_headers. A browser refuses to start the worker without them.

License

MIT. Model weights are covered by their own licenses; see docs/MODELS.md.