Userscript Converter

A web app that converts Tampermonkey/Greasemonkey userscripts into cross‑browser Manifest V3 extensions. The generated ZIP can be loaded in Chrome or Firefox and uses the native userScripts API to inject the userscript.

Features

• Registers scripts with chrome.userScripts.register in a sandboxed world.
• Generates a manifest.json with host permissions, optional_permissions: ['userScripts'], and a minimum_chrome_version of 120.
• Provides a Greasemonkey API polyfill (GM_* functions, unsafeWindow, etc.) via userscript_api.js.
• Supports dynamic code execution by configuring the user‑script world with a relaxed CSP (script-src 'self' 'unsafe-eval' blob:).
• Exposes the latest JSON response on window.z and includes a helper to safely evaluate dynamic element expressions.
• Includes both background.service_worker and background.scripts entries for Chrome and Firefox compatibility.

Development

npm install
npm run dev

Build

npm run build

The built files are output to dist/.

Deployment

Pushes to main trigger the GitHub Actions workflow in .github/workflows/deploy.yml which builds and publishes the site to GitHub Pages.

Using the generated extension

1. Build or convert a userscript through the web UI to obtain a ZIP archive.
2. Extract the ZIP and load it as an unpacked extension.
   • Chrome: visit chrome://extensions, enable Developer mode, choose Load unpacked, and select the extracted folder. Open the extension’s Details page and enable Allow User Scripts (or enable the #enable-extension-content-script-user-script flag on older versions).
   • Firefox: open about:debugging, choose This Firefox, click Load Temporary Add-on, and select manifest.json. Grant the requested permission when prompted. If you enable the permission later from the add-on's details page, the extension will now detect the change and register automatically without requiring a manual reload.

After these steps the userscript is registered and runs on matching pages using each browser’s native user‑script engine.

Feedback and Issues

Have suggestions or found a bug? Please visit feel free to open issues or provide feedback.

If you'd like to support the project, consider donating via PayPal.