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…	5	19441	September 30, 2025
About the Development category	0	4615	May 21, 2015
tabGroups query	2	44	October 17, 2026
Creating a WebExtensions extension that works in multiple browsers	2	865	October 5, 2026
Corrupted sessionstore.jsonlz4 file? issue	1	53	September 25, 2026
How to create a discarded tab with favicon loaded?	4	111	September 19, 2026
Unable to generate API key	3	91	September 11, 2026
How to detect / identify PWA (web apps) windows?	1	83	September 7, 2026
Add-on API key request email rate limit issue	1	63	August 26, 2026
Is it possible to modify the context menu display name for a dictionary? learning	0	57	July 19, 2026
Why malicious extensions get deleted "silently" ? how about transparent "Tombstone" pages instead feedback , issue	2	173	July 17, 2026
_paranioa_allocator_ virus mozilla subprocess insecure. offering solutions issue	0	51	July 16, 2026
Does a "Reading manifest" warning prevent install/update for regular users? (data_collection_permissions for ESR 115)	4	114	July 14, 2026
AMO won't let me re-upload version 2.9.3 after I deleted my previous 2.9.3 upload, and I can't delete the whole extension to start over issue	1	74	July 13, 2026
Mozilla Review Delays Preventing My Self-Distributed Extension Registration add-on-reviews	2	127	July 1, 2026
[Feedback] VoxSub – a Firefox add-on for dual subtitles, AI translation, and subtitle control webextensions-api , feedback	8	392	June 25, 2026
Requesting `file:///*` permission dynamically via `browser.permissions.request()` webextensions-api , permissions	1	146	June 24, 2026
You should make a "How to make an extension" video for vibe coders	3	136	June 22, 2026
Locked Dashboard: Clarification on False Positive (UUID: b0dd6398-1c58-4940-b0be-3577cd03b723) add-on-reviews	2	68	June 15, 2026
YouTube embed in extension no longer possible?	0	74	June 11, 2026
Cannot load extensions with background scripts	5	5227	June 8, 2026
[Showcase] Building a Global Media Controller for Firefox (Proof-of-Concept) learning , gb-media , webextensions-api , issue , manifest-v3	2	116	May 23, 2026
Extensions panel uses wrong themed icon colour	0	48	May 19, 2026
Problem with internationalisation management learning	10	149	May 6, 2026
Appeal: RavenWallet removal was triggered by coordinated fake review attack	8	145	April 29, 2026
Add-On code help	1	86	April 25, 2026
Strongly recommend adding hook native JavaScript function functionality feedback , issue	1	87	April 23, 2026
Add-On Removed and account Banned issue	1	126	April 21, 2026
How to attach cookie to request?	2	111	April 21, 2026
UnknownError: The operation failed for reasons unrelated to the database itself and not covered by any other error code	0	85	April 19, 2026

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…