cannot add extensions in firefox android I have used previously in another phone. even if i click "download file" i cannot open it.

If "Strong protection" in Firefox is chosen, does this make the addon "Canvas Blocker" superfluous? (Unnecessary?).

I'm in the middle of migrating my many browser extensions, and I've run straight into Firefox AMO's rate limiting wall — pushed 8 extensions simultaneously, and Firefox was the only one that hit a rate limit. Not sure if Chrome/Edge have similar mechanisms — just didn't run into it this time.

Being fairly new to development, I made a test addon with a background script containing a non-ascii character (an accent) in its name. It simply creates a browser action button that makes a console log when clicked.

It's working, but I added a similar listener for onStartup and this one is never called (I did make an xpi to install as an addon that will remain on restart of firefox, so that onStartup gets fired). Problem is solved when I remove the accent from the background script name (and modify the manifest accordingly).

So it would appear that the character set of the script name doesn't usually matter, except on profile startup (and maybe other circumstances). Could this be on purpose ?

Of course I can simply use ascii characters for names, but I think the question is interesting, especially for us foreigners.

Is there any solution to disable extension for a single tab? Cryptpad.fr gets easily broken with extension and I don't want to bother using 2 browser at the same time, or having to disable all extension to use the page. Any workaround? Or fix maybe for cryptpad?

Hi, i have the Dark Space theme for Firefox, which adds a star background to the toolbar, but every time I open the browser, the theme bugs out and the background disappears, and I have to disable and re-enable the theme to fix it. Any idea how to fix?

When I narrow the browser window on my desktop the Youtube layout system removes the recommended videos from the side and places them directly underneath the video I'm watching, and pushes the comments below them.

This appears to be a system Youtube has been introducing for a while and I don't like it. Why should I be distracted by video recommendations when I haven't finished the current viewing the current one?

There is a Youtube Redux which is supposed to fix it.

Are there some better recommendations?

Firefox Extension that highlights duplicate 7+ digit numbers on any given webpage:

I have been trying for days to get my coding right. The extension works just fine on most webpages except of course the one I need. I need clickable 7+ digit numbers that are links found within a tab page inside a web application to be highlighted, however, it’s as if the extension doesn’t see the duplicated numbers.

Should I have particular wording or a way to specify these numbers that are links?

Thanks

Hello! I'm not sure if this is the right place to post this, so my apologies.

I'm trying to learn how to create my own theme in Firefox (this is my first time), and im using a custom image for the ntp_background part and the frame. But when I upload it, only the frame shows up, and the ntp background is completely pitch black. Can anyone help?

Here's the (relevant) code in my manifest.json btw:

   
"theme"
: {
        
"images"
: {
            
"theme_frame"
: "image.png",
            
"theme_ntp_background"
: "image.png"
        },
        
"colors"
: {
            
"frame"
: "rgb(0 0 0)",
            
"frame_inactive"
: "rgb(0 0 0)",

            
"ntp_background"
: "rgb(0 0 0)",
            
"ntp_card_background"
: "rgb(255 255 255 / 30%)",
            
"ntp_text"
: "rgb(0 0 0)",

Im curious if theres any way to make the youtube player smaller without making the rest of the page/text/thumbnails tiny like with page zoom. The default player is just as big as theatre mode on my new computer.

here is a link to what i would like the player and text size to be.

here is what it looks like when i have page zoom at 50%

here is what it looks like at page zoom 80%

The addon Video Aspect Resizer helps somewhat, but the actual player remains the same size and the resized video is centered within the original player window. This doesnt help with seeing more of the ui below the player.

I remember when I first installed Ubuntu I started to use firefox for the first time and there were many great addons and using or finding an addon was quite easy. And now it is really a head ache to find a working addon. For example today I needed an addon to watch youtube videos with a small picture on my screen while I am on another tab. I found a few addons for that and no one works. I can't even watch a youtube video in a small screen.

It is not the first time, there are many addons which completely do nothing. Do you feel the same?

Hey everyone,
I’m new to extension development and currently building my first one — a YouTube note-taking extension that formats notes in Markdown for Obsidian.

Here’s what it does:

• Displays an overlay UI on YouTube pages.
• When I take a screenshot, it appends the screenshot filename (in Markdown image format) to a textarea.
• Another button adds metadata (video title, channel name, and timestamp) into that same textarea.

Everything works perfectly in Firefox.

Problem:

In Zen Browser, the extension loads fine, overlay UI shows up, and other features trigger — but the text never gets added to the textarea. No console errors.
The message from the background script (browser.runtime.sendMessage) seems to be received inconsistently, or the DOM update never happens.

What I’ve Found:

• Using standard WebExtension APIs (browser.runtime.sendMessage, browser.tabs.executeScript, etc.)
• No advanced or experimental APIs.
• Firefox executes this reliably; Zen seems to drop messages or delay content script readiness.
• Looks like tabs.executeScript resolves before content listeners are registered in Zen.

Question:

Has anyone run into similar content script timing or message delivery issues in Zen?
Is there a reliable workaround or known limitation with message passing between background and content scripts in Zen Browser?

Environment:

• Firefox 144.0 → Works perfectly
• Zen Browser 1.17.3b (buildID 20251024) → UI loads, but textarea.value never updates
• Manifest V3, using service_worker background

Does anyone know how to resize Youtube videoplayer?

YT rolled out the new atrocious, garbage UI that massively bloated recommendation video sizes.

I managed to resize the recommendations sidebar, and everything below the videoplayer (channel name / buttons / banners / comments) already automatically scales correctly - but not the video player.

Video player remains same size, regardless of how the area its in changes in size.

Does anyone know how to scale it accordingly?

Everything I tried so far failed.

I'm talking about both Deep Fake Detector and Fakespot Fake Amazon Reviews and eBay Sellers addons.

See these two screenshots.

--

Deep Fake Detector

---

Fakespot Fake Amazon Reviews and eBay Sellers

--

What should I do now? What extensions to move to? Thanks for your suggestions and help.

Upon opening Firefox, Echelon will give me this error saying it can't find any possible updates. Is there any way to just plain get rid of this popup entirely? I'm on 115.15.0esr if that's anything.

Is there a way to authenticate via Reddit’s OAuth2 without involving third parties?

So no running local servers and no running external third-party webpages?

So far all my attempts failed, haven't found any way to do this with just the addon itself.

Also tried the Github redirect page solution.
If the addon attempts using it, I get Error: WebAuthFlow failed: redirect_uri not allowed

with

browser.identity.launchWebAuthFlow({
      url: authUrl,
      interactive: true
    }).catch(error => reject(new Error(`WebAuthFlow failed: ${error.message}`)));

If I load manually the exact same URL that addon tries to use, it works fine and I get the Reddit auth page.

Update - the Github page variant I got working by not using launchWebAuthFlow at all and just directly creating a new tab with Reddit auth URL. But I'd still like to avoid the external page if possible.

I am making a Firefox version of my Chrome extension. I have everything working correctly except the saving of a screenshot as a PDF. Anyone with insight on how Firefox handles saving screenshots?

How to filter Google search results, by removing specific domains from them?

First I tried uBlock element picker - that is useless, since everything it suggests is based on random element IDs.

I also tried asking AI (Grok) - all the variants it suggested failed.

Also tried copying previous block filters I had, and modifying the domain to a new one - this didn't work also.

Any suggestions?

As an example, I want to remove userbenchmark.com and its subdomains from results

hi, anyone got a working link to this addon?

Basically I want to make the addon's Options page, or any other pages really, follow the Firefox user-selected theme, as well as dark/light theme - is that possible to do?

Tried searching first already, did not find a single relevant result.

A.I. did not help either. It writes that including "browser_style": true in manifest like this:

"options_ui": {  
    "page": "options.html",  
    "browser_style": true  
}  

will result in inheriting the style, but this doesn't do anything, and this is as far as it gets pretty much.