Firefox 149 bundles content-blocking engine adblock-rust

[UCyborg]

https://www.privacyguides.org/news/2026/04/24/firefox-quietly-adds-braves-rust-based-adblocker/

Currently behind about:config pref and no UI to configure it. Compatible with uBlock Origin's filters / syntax.

[Night Wing]

I am not a fan of "built in adblockers" like Brave has and this is just one reason I do not use the Brave browser as a backup to Pale Moon. My other two browsers are Waterfox and Firefox where Firefox comes installed by default in the MX Linux and Debian linux distros.

If Firefox decides to do this and turns it on by default in a future version, I will turn it off in Settings. If this "new feature" is not in Settings, then I will go into "about:config" and turn it off from there. If for some reason, the about:setting does not take after a reboot, then I will use the linux (ugh!) Terminal to turn if off "permanently".

Since this adblock-rust seems to be borrowing "stuff" from the uBlock Origin extension, I'd rather use Raymond Hill's extension for both Firefox and my backup Waterfox.

https://addons.mozilla.org/en-US/firefo ... ck-origin/

I do get the gist of reducing memory usage which could encompass a large percentage, but this desktop tower computer I am typing this post with has 64 GB of memory in it so for me memory usage is "not" in short supply.

But for discussion's sake and being hypothetical, lets say Firefox goes "off the rails" in the future and keeps putting lots and lots of more "stuff" into Firefox and I need more memory than 64 GB's. The motherboard in this tower can access up to 128 GB's.

Then I would purchase four, 32 GB "sticks" for my four memory slots on this motherboard since two slots are not being used (empty) at this time. This is one of the reasons why I purchased this motherboard for this mid size Montech gaming tower computer I am now using.

The old adage of; "Better to have it and not need it, than to need it and not have it".

[ownedbywuigi]

https://www.privacyguides.org/news/2026/04/24/firefox-quietly-adds-braves-rust-based-adblocker/

Currently behind about:config pref and no UI to configure it. Compatible with uBlock Origin's filters / syntax.

Of fucking course it's a Rust based thing. The writing is in the wall, Mozilla, nobody wants Rust.

[andyprough]

Firefox getting built-in content blocking could mean Mozilla is going to give up on Manifest v2 extension support and cave in to Google's Manifest v3, which does not allow full content blocking extensions such as uBlock's regular version.

Which would be an ironic twist - Pale Moon and Basilisk would be the only remaining browsers with the ability to run unlimited content blocking extensions.

[Gemmaugr]

Firefox getting built-in content blocking could mean Mozilla is going to give up on Manifest v2 extension support and cave in to Google's Manifest v3, which does not allow full content blocking extensions such as uBlock's regular version.

Which would be an ironic twist - Pale Moon and Basilisk would be the only remaining browsers with the ability to run unlimited content blocking extensions.

My thoughts exactly!

Especially with how it's worded here: https://blog.mozilla.org/addons/2021/05 ... v3-update/

Code: Select all

We will support blocking webRequest until there’s a better solution which covers all use cases we consider important

We have not yet set a deprecation date for Manifest v2 but expect it to be supported for at least one year after Manifest v3 becomes stable in the release channel.

[Night Wing]

Firefox getting built-in content blocking could mean Mozilla is going to give up on Manifest v2 extension support and cave in to Google's Manifest v3, which does not allow full content blocking extensions such as uBlock's regular version.

Which would be an ironic twist - Pale Moon and Basilisk would be the only remaining browsers with the ability to run unlimited content blocking extensions.

I agree with the two statement above. And I will now come at this from a "money" angle.

Alphabet owns Google so I will now use Google to make my point.

Google created the Chrome browser. Google also owns YouTube. So if a Chrome user wants to visit YT and watch some videos, they will have to watch an advertisement before they get to see the video. And this could be two or more advertisements. This is because in Chrome while visiting YouTube, you can only use uBlock Origin Lite which does not block advertisements. uBlock Origin Lite is "totally useless" as an adblocker.

Now Mozilla (and Firefox) is being kept afloat because Google, under contract, gives Mozilla somewhere between $400-$500 million dollars to keep Google as the default search engine in Firefox.

So lets say at contract renewal time, Google comes up with this offer for Mozilla. The offer states; "Mozilla will get this money, but they will have to use "adblock-rust-lite which is just another uBlock Origin Lite when any Firefox user is visiting YouTube".

Mozilla might say to Google, "We need to mull this offer over and we will give you (Google) an answer in one weeks time". Then Google might say; "Mozilla can think about this offer, but the offer EXPIRES in one hours time".

I do not think the higher ups at Mozilla (CEO, Vice President, etc) or even the Board of Directors will say, "no" to this offer because none of them want to lose their very high yearly salaries. Mozilla will fold like a cheap $50 dollar suit.

If this does come to pass, then I think this song below from 1973 back then, will be appropriate for today in 2026 if you get my drift.

The O'Jays - "For The Love Of Money".

https://www.youtube.com/watch?v=ruAEx1b ... uAEx1bv1ig

[ron_1]

Google created the Chrome browser. Google also owns YouTube. So if a Chrome user wants to visit YT and watch some videos, they will have to watch an advertisement before they get to see the video. And this could be two or more advertisements. This is because in Chrome while visiting YouTube, you can only use uBlock Origin Lite which does not block advertisements. uBlock Origin Lite is "totally useless" as an adblocker.

I don't get ads on YT using Chromium and uBlock Origin Lite. I have filtering mode set to complete. I don't get any ads.

[ownedbywuigi]

Firefox getting built-in content blocking could mean Mozilla is going to give up on Manifest v2 extension support and cave in to Google's Manifest v3, which does not allow full content blocking extensions such as uBlock's regular version.

Which would be an ironic twist - Pale Moon and Basilisk would be the only remaining browsers with the ability to run unlimited content blocking extensions.

My thoughts exactly!

Especially with how it's worded here: https://blog.mozilla.org/addons/2021/05 ... v3-update/

Code: Select all

We will support blocking webRequest until there’s a better solution which covers all use cases we consider important

We have not yet set a deprecation date for Manifest v2 but expect it to be supported for at least one year after Manifest v3 becomes stable in the release channel.

“Not yet”

The writing is on the wall. I think when Mozilla gives up on Manifest V2, either some FX forks will keep v2 or a surge of people will be downloading Goanna browsers.

[gabrgv]

I think when Mozilla gives up on Manifest V2, either some FX forks will keep v2 or a surge of people will be downloading Goanna browsers.

Honestly, I think you're overestimating the so-called "principles" of these people. Remember that recently Mozilla introduced a new Term of Use for Firefox and everybody complained, but nothing changed. More recently, they added AI crap to the browser, and same thing.

Of course, it certainly would be handy if a surge of people came to the UXP world, though.

Off-topic:
I was kind of foreseeing this scenario when I amicably remarked to the devs here how it could be hard for a "normal" PC user (not you or me) to find and install an ad blocker for Pale Moon or Basilisk. Got my mouth shut real quick then. Obviously, I was misinterpreted, partially, I think, because I don't know how to express myself in english very well, and because people have a hard time reading nowadays.

[andyprough]

I don't get ads on YT using Chromium and uBlock Origin Lite. I have filtering mode set to complete. I don't get any ads.

Enjoy your ad-free experience while you can. Google now has complete control over what blocking is allowed via extensions, and can either take away your blocking or implement unblockable ads at any time they desire.

[ron_1]

Enjoy your ad-free experience while you can. Google now has complete control over what blocking is allowed via extensions, and can either take away your blocking or implement unlockable ads at any time they desire.

I have no doubt about this. If it comes to that, I'll get them another way without ads.

[Night Wing]

I don't get ads on YT using Chromium and uBlock Origin Lite. I have filtering mode set to complete. I don't get any ads.

At the computer shop where some users come in as customers, they are not real tech savvy when using Firefox. When I go and check their Settings in Firefox, they have never changed any of the default settings.

So I do not think these same customers will be changing any settings in the filtering mode for this new built in adblocker if this new "feature" becomes the default (turned on) in Firefox by Mozilla.

[Night Wing]

The writing is on the wall. I think when Mozilla gives up on Manifest V2, either some FX forks will keep v2 or a surge of people will be downloading Goanna browsers.

Alex's Waterfox browser does not exactly follow Mozilla's line to the letter so I am hoping he keeps Manifest 2. I really like Waterfox as a backup browser to Pale Moon.

[ownedbywuigi]

The writing is on the wall. I think when Mozilla gives up on Manifest V2, either some FX forks will keep v2 or a surge of people will be downloading Goanna browsers.

Alex's Waterfox browser does not exactly follow Mozilla's line to the letter so I am hoping he keeps Manifest 2. I really like Waterfox as a backup browser to Pale Moon.

I know for sure r3dfox will keep Manifest 2 aswell, maybe IceCat too.

[andyprough]

Alex's Waterfox browser does not exactly follow Mozilla's line to the letter so I am hoping he keeps Manifest 2. I really like Waterfox as a backup browser to Pale Moon.

Alex likely won't have a choice - maintaining Manifest V2 by himself is likely too much of a challenge for one developer. Although if anyone could do it, it would be Alex. He kept that Waterfox Classic alive for years.

[Night Wing]

]Alex likely won't have a choice - maintaining Manifest V2 by himself is likely too much of a challenge for one developer. Although if anyone could do it, it would be Alex. He kept that Waterfox Classic alive for years.

At this time I have one saving grace. Pale Moon is my daily driver browser wise. Waterfox is the backup browser. I only use Waterfox when some sites do not render properly or if I cannot get to them when I am using Pale Moon. Then I switch over and use Waterfox. So I should be limited in seeing lots of ads since I am using Pale Moon the majority of time.

As for Firefox, it is the default browser which comes with MX Linux and Debian. I do not use Firefox very much. Speaking just for me, Firefox in these two linux distros is "out of mind and out of sight" since Pale Moon and Waterfox are carrying the work load.

[andyprough]

As for Firefox, it is the default browser which comes with MX Linux and Debian. I do not use Firefox very much. Speaking just for me, Firefox in these two linux distros is "out of mind and out of sight" since Pale Moon and Waterfox are carrying the work load.

I use Firefox for just one thing on new systems - to download Pale Moon. And then I immediately 'sudo apt purge firefox*' it from my system.

And of course, I don't even need to do that on MX, as it already has Pale Moon in its mx-packageinstaller. So on a new MX installation, I just immediately 'sudo apt purge firefox*' as the first order of business.

[vannilla]

I haven't read the thread or the article and I don't care about the adblock, I am simply going to be grumpy and comment like this: remember when they told us Mozilla had to remove such-and-such feature because it was a maintenance burden?

[gabrgv]

This really looks like they are preparing to move toward the adoption of Manifest V3, as a built-in ad blocker wouldn't be subject to V3's limitations, I guess. It would be significantly faster too. But if uBlock Lite blocks everything all the same, why bother then?

For those wondering, looks like Waterfox took this road before Firefox.

[Gemmaugr]

For those wondering, looks like Waterfox took this road before Firefox.

Not sure about that. Firefox opened this 3 months ago (https://bugzilla.mozilla.org/show_bug.cgi?id=2013888), while Waterfox's is from just one month ago.