- 1 A Cross-Browser API for Developing Add-ons
- 2 Timelines and roadmaps
- 3 Migration paths for developers of legacy add-ons
- 4 Don't See the WebExtensions APIs You Need?
- 5 Tools
- 6 Documentation & Tutorials
- 7 Blog Posts
- 8 Add-on Developer Communication Calendar
- 9 Get in Touch
A Cross-Browser API for Developing Add-ons
The technology for developing add-ons is in transition to WebExtensions APIs. These APIs let you create and maintain one codebase that works across multiple browsers, without having to update it for every Firefox release.
With the release of Firefox 57 in November, only add-ons built with WebExtensions APIs will be supported.
This page contains timelines, tutorials, and other resources to help you port your legacy add-on to use WebExtensions APIs. If you're looking for resources on creating a new add-on, please head over to MDN.
- Office Hours support available for transitioning developers - Check the schedule to see who can help in your time zone.
- Use Embbeded WebExtensions to port your stored data
- WebExtensions Experiments: prototype WebExtension APIs without having to build Firefox
- Help plan and prioritize (or vouch for) WebExtensions APIs by joining the bi-weekly public triage.
Timelines and roadmaps
- Add-on planning (private): see what the add-on team is working on
- Add-on impacting changes and visual schedule: see upcoming changes that will impact compatibility
- WebExtensions roadmap: see upcoming APIs.
Migration paths for developers of legacy add-ons
1) SDK add-on
2) XUL or XPCOM add-on
Here is the comparison chart showing XUL/XPCOM APIs and their WebExtensions counterparts. If you don't see the APIs you need to port to WebExtensions, please take a look at some more options below.
Don't See the WebExtensions APIs You Need?
- If you're experienced with Mozilla infrastructure and would like to develop WebExtensions APIs directly for Firefox, here is a list of approved APIs that you can start contributing to.
- If you want to prototype and tinker with WebExtensions APIs without having to build Firefox, WebExtensions Experiments is for you!
- If you want to request a new WebExtensions API, please read this page.
Embedded WebExtensions - Up until Firefox 57 you can embed a WebExtensions add-on inside an existing SDK or bootstrapped add-on. This is especially useful to developers of SDK or bootstrapped add-ons who want to start migrating to WebExtensions and take advantage of new APIs like Native Messaging, but can’t fully migrate yet. It’s also useful for developers who want to complete data migration towards WebExtensions, and who want to take parts of their add-on that are not compatible with multiprocess Firefox and make them compatible.
Not all add-ons will be able to migrate to WebExtensions without having to drop any features. But we want to work with you to get as many add-ons migrated as possible with the functionality you created intact. We invite you to contribute to its evolution, and we look forward to working with you.
- web-ext is a command line tool designed to speed up various parts of the WebExtension development process, making development faster and easier.
- Lookup tool to check your add-on type and get porting resource recommendations
- Embbeded WebExtensions are available to port your stored data
- WebExtensions Helper speeds up browser add-ons development by providing facilities for WebExtensions-based (Firefox, Chrome, Opera and Edge) extensions
- Chrome Extension generator creates everything you need to get started with extension development. You can choose Browser UI(Browser,Page Action, Omnibox) type and select permissions you need.
- Extensionizr is a wizard that helps you create a basic extension
- Chrome Boilerplate
- Skeleton Chrome Extension is an extension bootstrap and template
Documentation & Tutorials
- Porting guides that map SDK and XUL APIs to available WebExtensions APIs
- How-to guides covering common add-on developer cases, like intercepting web requests and adding a button to the toolbar
- Comparison with the Add-on SDK
- Comparison with XUL/XPCOM extensions
- Browser compatibility table for all WebExtensions APIs
- Examples of WebExtensions on MDN Web Docs
- @iamvp7's Tutorials & examples of WebExtensions
All WebExtensions blog posts are here.
- August 11, 2017: WebExtensions in Firefox 56
- August 3, 2017: Extension Examples: See the APIs in Action
- June 14, 2017: WebExtensions in Firefox 55
- May 16, 2017: Add-on Compatibility for Firefox 55
- May 10, 2017: Incompatible change to sessions.restore API in Firefox 54
- Apr 3, 2017: Migrating ColorZilla to WebExtensions
- Mar 27, 2017: Update on Compatibility Milestones
- Mar 24, 2017: Migrating AdBlock for Firefox to WebExtensons
- Mar 17, 2017: Migrating to WebExtensions? Don't Forget Your Users
- Mar 13, 2017: WebExtensions in Firefox 54
- Mar 9, 2017: Office Hours Support for Transitioning and Porting to WebExtensions
- Feb 16, 2017: The Road to Firefox 57 – Compatibility Milestones
- Jan 25, 2017: WebExtensions in Firefox 53
- Jan 20, 2017: Migrating to WebExtensions: port your stored data
- Dec 16, 2016: Meet Some Nifty New WebExtensions
- Nov 23, 2016: Add-ons in 2017
- Nov 22, 2016: webextensions-examples and Hacktoberfest
- Nov 18, 2016: WebExtensions in Firefox 52
- Nov 3, 2016: More ways to contribute to WebExtensions
- Sep 29, 2016: WebExtensions in Firefox 51
- Sep 28, 2016: How Video DownloadHelper Became Compatible with Multiprocess Firefox
- Sep 13, 2016: WebExtensions and parity with Chrome
- Aug 25, 2016: WebExtensions in Firefox 50
- Aug 12, 2016: WebExtensions Taking Root
- July 27, 2016: Linting and Automatically Reloading WebExtensions
- July 21, 2016: New WebExtensions Guides and How-tos on MDN
- July 14, 2016: WebExtensions support on AMO
- June 9, 2016: WebExtensions in Firefox 49
- May 9, 2016: Results of the WebExtensions API Survey
- Apr 29, 2016: WebExtensions in Firefox 48
- Apr 26, 2016: Migrating Popup ALT Attribute from XUL/XPCOM to WebExtensions
- Apr 14, 2016: Developing Extensions With Web-ext 1.0
- Mar 30, 2016: Tinkering with WebExtensions
- Mar 14, 2016: Advantages of WebExtensions for Developers
- Mar 11, 2016: WebExtensions in Firefox 47
- Feb 2, 2016: WebExtensions in Firefox 46
- Jan 9, 2016: WebExtensions First Impressions
- Dec 21, 2015: WebExtensions in Firefox 45
- Aug 21, 2015: The Future of Developing Firefox Add-ons
Add-on Developer Communication Calendar
Get in Touch
- #teamaddons: team chat
- #addons: support for extensions, themes, plugins and addons.mozilla.org
- #addon-reviewers: add-on reviews and policy
- #amo: addons.mozilla.org bugs and development
- #extdev: extension development
- #themedev: theme development
- #webextensions: web extensions
- Mailing Lists:
- More ways to get in touch:
- Office Hours for migration support: https://atsay.github.io/WebExtensions_office_hours/
- Blog: https://blog.mozilla.org/addons/
- Forum: https://discourse.mozilla-community.org/c/add-ons