Development

Topic	Replies	Views	Activity
Get started with Firefox extension development Extensions provide a simple and powerful way to personalize your browsing experience. If you know JavaScript, CSS, and HTML, you can build your own. If you are brand-new to add-on development, you can get started by che…	6	16786	September 30, 2025
About the Development category	0	4526	May 21, 2015
Is Firefox MV3 intentionally not supporting `browser.runtime.onMessage` in MV3 userScripts API? Why?	8	129	January 21, 2026
Why does runtime.onSuspend not execute window.localStorage.setItem? learning , issue	2	17	January 19, 2026
Questions about including third-party libraries	0	16	January 19, 2026
How does Mozilla calculate daily users in the statistics panel?	0	32	January 5, 2026
How to automate add-on option screen tests?	7	203	December 30, 2025
Firefox Default Themes & Theme Values	2	36	December 24, 2025
Insert text into textbox with add-on click learning	2	64	December 15, 2025
How to prevent redirecting to HTTPS when fetching local address from a background script?	2	32	December 3, 2025
Do older Firefox versions ignore "data_collection_permissions"?	2	188	December 3, 2025
A way to set tab context as default for new tab	3	85	November 18, 2025
[EDITED] Error: Permission denied to access property "then" issue , manifest-v3	4	2190	November 18, 2025
Funcions `loadOneTab` and `loadURI` in 2023 in Firefox Experimental API?	2	696	November 16, 2025
Foucs behavior issue on sidebar when opening	1	36	October 29, 2025
Pin Tab Enhancement / Side Bar Control	2	308	October 25, 2025
[Manifest V3] background script stopped when signed extension is up	3	72	October 15, 2025
WebExtension API support for web app windows	3	93	October 10, 2025
IDEA - Add Unsubscribe Footer thunderbird	0	37	October 5, 2025
Validation says data_collection_permissions missing, but exists in manifest? issue	2	850	September 20, 2025
Do extension settings reference or depend on the extension's internal uuid?	2	29	September 19, 2025
Can we access location of new tab wallpaper?	2	48	September 15, 2025
License: This field, or custom_license, is required for listed versions	3	80	September 12, 2025
Error when use web-ext with chrome with `--keep-profile-changes`? issue	3	96	August 29, 2025
How to restore a recently-closed tab group via WebExtensions API	2	243	August 28, 2025
Does web-ext not load extension when use with Chrome? learning , issue	3	60	August 28, 2025
WebExtError when signing but still succeed? issue	1	40	August 25, 2025
What happens to storage when a user updates the extension? updates	1	50	August 17, 2025
Accessing closed tab groups	4	272	August 11, 2025
Deleting All Bookmarks in Folder (weird Fx bug?)	8	117	August 8, 2025

Get started with Firefox extension development

Extensions provide a simple and powerful way to personalize your browsing experience. If you know JavaScript, CSS, and HTML, you can build your own. If you are brand-new to add-on development, you can get started by che…