Firefox uses the Promise-based browser namespace. Automated solution: Use the WebExtension Polyfill by Mozilla:
| Strategy | Pros | Cons | |----------|------|------| | | Full control | Duplicate work | | Single codebase + polyfill | One source, runtime adaptation | Slightly larger bundle | | Build-time flag | Clean separation | Requires build system | convert chrome extension to firefox
"background": "scripts": ["background.js"], "persistent": true Firefox uses the Promise-based browser namespace
Date: April 17, 2026 Subject: Technical feasibility, methodology, and compatibility analysis for migrating Chrome extensions to Firefox (Manifest V3 focus). 1. Executive Summary Migrating a Chrome extension to Firefox is not a direct "drag-and-drop" process, but it is highly feasible. Firefox supports the majority of Chrome’s Extension APIs (often via the browser namespace instead of chrome ). The primary complexity lies in Manifest V3 differences, service worker vs. background page handling, and Firefox’s stricter privacy policies regarding cross-origin requests and remote code execution. Executive Summary Migrating a Chrome extension to Firefox
Run your extension through web-ext lint and test in Firefox Nightly. For a detailed API compatibility matrix, refer to: Mozilla’s Chrome incompatibilities doc
"browser_specific_settings": "gecko": "id": "your-extension@domain.com", "strict_min_version": "109.0"