Forum der Gemeinschaft Firefox

Hello

I have Firefox 154.0 on my 2 PCs that have Windows 11 and both computers are updated fully as of 22nd August 2026 with both Windows updates and Nvidia drivers.

Background: On my 2 PCs I have an "old" stationary PC with Geforce 1070 TI card, and I have a laptop Asus Vivobook 15 PRO with a Geforce GTX 4600 card. Both computers working fine and no issues so far.

Symptoms: I updated Firefox. Note! I always update Firefox on my computers, so it wasn't a clean install of the browser. And suddenly on both computers there were black artifacts all over screen and flickering when scrolling on Facebook or Youtube. Also even worse on sites were you drag a div and the browser turns into a 1-bit disco.

Workaround that seems to be working for me: I went to about:settings and searched for hardware on my laptop (the one with 4600 card) and searched for "hardware". Then I disabled the hardware acceleration thing, or whatever it was, but unchecking the result after search. Then I restarted my laptop not using hardware acceleration and it worked fine.

Then again I search about:settings for hardware and checked the bottom of the 2, not sure what the first one was. And restarted computer.

Now I don't have those black artifacts and flickering any more.

Not sure if that somehow triggered something that works for fresh installs or not.

Anyway... I can't submit a ticket since I can't reproduce the error it's no point submitting to Bugzilla. But hopefully this makes sense anyways... But I'm pretty sure you guys are aware of this issue already. But posting anyways in case it might help.

My hardware is low end from 2016, Pentium 3825U, HD Graphics, and 4gigs of RAM. In the old times, the browser was fast, but this year it has slowed down so bad. I needed to switch to Thorium browser because Firefox became so heavy, using too much RAM and CPU. Please make the browser light, fast, and good for old systems again! (I want to use Firefox back)

My font on some sites is being forced to this horrible condensed font and it's seemingly nothing to do with my font settings in browser. Thing is, I VAGUELY remember changing a setting SOMEWHERE to actually do this, but it's not the main font setting in accessibility. Furthermore this issue has only started happening in the last day or two and my vague memory of setting my font somewhere was years ago.

Is there any other setting in Firefox that affects default font for certain sites?

[Images attached from terraria.wiki.gg in a normal tab (with bad font) and private browsing tab (with the font it SHOULD have) for comparison]

(AI written summary of troubleshooting steps taken before making this support thread)

Firefox version: - 152.0.1 Release - 153.0 Nightly

OS: - Windows 11 build 26200

GPU: - NVIDIA GeForce RTX 4070 SUPER

Codec package: - Microsoft HEVC Video Extensions installed from Microsoft Store

Problem

Firefox does not expose HEVC playback support, causing Twitch to disable 1440p streams encoded with HEVC.

The same machine can play the same HEVC Twitch streams in Chrome immediately after installing HEVC Video Extensions.

Expected result

Firefox should report HEVC playback support and allow playback of HEVC streams, as Chrome does on the same system.

Actual result

Firefox reports HEVC as unsupported.

about:support:

codecSupportInfo: H264 SWDEC HWDEC VP9 SWDEC HWDEC VP8 SWDEC HWDEC AV1 SWDEC HWDEC HEVC NONE

Troubleshooting already performed

- Installed Microsoft HEVC Video Extensions - Rebooted Windows - Updated NVIDIA drivers - Verified hardware acceleration is enabled - Tested with a brand new Firefox profile - Tested with Firefox Nightly - Confirmed Chrome can play the same HEVC streams

Additional observations

Chrome: - Twitch 1440p becomes available immediately after installing HEVC Video Extensions - Twitch Stats for Nerds reports:

 hev1.1.6.L150.90.0.0.0.0.0

Firefox: - Twitch reports that the browser does not support the required resolution - 1440p remains greyed out - about:support continues to report HEVC NONE

Reproducible tests

Firefox console:

MediaSource.isTypeSupported('video/mp4; codecs="hev1.1.6.L150.90"')

Result: false

MediaSource.isTypeSupported('video/mp4; codecs="hvc1.1.6.L150.90"')

Result: false

navigator.mediaCapabilities.decodingInfo({

 type: "media-source",
 video: {
   contentType: 'video/mp4; codecs="hev1.1.6.L150.90"',
   width: 2560,
   height: 1440,
   bitrate: 8000000,
   framerate: 60
 }

})

Result: {

 supported: false,
 smooth: false,
 powerEfficient: false

}

For comparison:

MediaSource.isTypeSupported('video/mp4; codecs="av01.0.08M.08"')

Result: true

navigator.mediaCapabilities.decodingInfo({

 type: "file",
 video: {
   contentType: 'video/mp4; codecs="av01.0.08M.08"',
   width: 2560,
   height: 1440,
   bitrate: 8000000,
   framerate: 60
 }

})

Result: {

 supported: true,
 smooth: true,
 powerEfficient: true

}

Additional note

Setting:

dom.media.webcodecs.h265.enabled = true

causes HTML5 codec test (https://html5test.co/) to report H.265 support, but does not change:

- about:support - MediaSource.isTypeSupported() - MediaCapabilities.decodingInfo() - Twitch HEVC playback availability

Question

Is this a known issue with HEVC Media Source Extensions support on Windows 11 build 26200, or is there another requirement for Firefox to expose HEVC playback capability through MediaSource and MediaCapabilities when the Windows HEVC codec is installed and functioning in Chromium-based browsers?

After updating from Firefox 154 to 155.0 on Windows 11, the download progress indicator on the Windows taskbar icon no longer appears at all.

What I see: - While a download is in progress, only the circular progress on the in-window Downloads button is visible. - There is no progress bar/fill on the Firefox taskbar icon, even when the window is focused and the Downloads panel is open. - In Firefox 154 this taskbar progress worked. - Chrome on the same PC still shows download progress on the taskbar correctly.

I checked about:config for anything related to taskbar/download progress and found nothing that controls this.

Is the Windows taskbar download progress still expected to work in Firefox 155, or was it removed/changed? Has anyone else noticed this?

Thanks.

Since the last update (I know that Firefox DE is a beta/semi-nightly release, I just want to know if this is my mistake or a bug), only my first firefox window has address bar, all the other windows don't. And when tabs are vertical, the rest of the windows don't even have a title bar. (This behavior doesn't apply to newly created windows) Also, non-primary windows also lose the capacity to resize the vertical tab bar. ¿Did I do something wrong or is this a bug?

Where is a link, icon, or ANY WAY to add a shortcut site to my Ubuntu FF **DESKTOP** homescreen?

I already have 4 rows (since 2013 over many Linux laptops. Ubuntu, Mint, popOS, and now Ubuntu 26.04 LTS).

There is room in the fourth row for a few more. BUT I don't see any icon or link or right-click option to add another!

Phrasing the article search various ways gets me a lot of unrelated stuff.

EVERY help article, of which there are few, seems to have a BIG-ASSumption that everyone is using mobile Firefox.

NO! NO three dots. No right click brings up anything. NOTHING in settings. I've been through everything in the 3-bar menu, and there is NOTHING. (I already use it to sync, go to OTHER settings, go to help, etc.)

This is a day after an update, though I don't know how that affects it.

Usually if I forget how I did something, I just explore and find it. BUT --

My way of adding new shortcuts seems to be GONE.

The last response was 14 August for numerous queries. All still outstanding in my support log. Am I looking at yet another failing brand that didn't adapt and whose market share crashed ? Just looking to get out now and find another browser. Astonishing. The bad moves and mismanagement... All there to read about from business analyses sites. Unbelievable.

Hi, I'm running FF 149.0 (64-bit) on Windows 11. I've used profiles for a while now and on several occassions I've "lost profiles". Currently I have three profiles which I set up and edited the icon and colour associated with each. When I launch FF I see the Profile Manager and can select any of the three and I can create a new profile which shows here. However, once in any one of the FF profiles I don't see the others - by which I mean that when I go via the hamburger lines top right and click on the current profile, the 'other profiles' section is blank. I also cannot edit the profile from using the edit pencil top right (after clicking the hamburger lines and clicking on the current profile), it takes me to about:editprofile but the page is completely blank. Confusingly, if I go to about:profiles I see two profiles, neither of which shows up in the Profile Manager! I'm going round in circles trying to understand where to edit my exisitng profiles and make sense of the five profiles that don't all show up in the same place!

The Firefox Browser crashed three four times last week. Mozzila Support team after study, gave a comment that RAM capacity is Low( 4 GB in my case , laptop). Does it sound OK? Why it does not happen with Chrome or Microsoft One edge Browser? I asked this to Google Gemini. The answer is as given below: Yes, the Mozilla Support team’s explanation sounds entirely accurate.A capacity of 4 GB RAM is extremely low for a modern laptop running an operating system like Windows 10 or 11 alongside modern web applications. The operating system itself routinely consumes 2 GB to 2.5 GB of RAM just to keep your computer running, leaving very little leftover memory for heavy multitasking. Both Google Chrome and Microsoft Edge use built-in "efficiency modes" and aggressive tab-sleeping algorithms. When your computer begins running out of RAM, Chrome and Edge will silently put inactive tabs to "sleep" to free up memory before the browser crashes. [1] (https://www.superchargebrowser.com/library/firefox-vs-chrome-ram-usage-2026/) Good Solutions to Fix the Crashes- 1. Software Adjustments (Free & Immediate)If you want to keep using Firefox smoothly on 4 GB of RAM, you need to minimize its memory footprint:Reduce Firefox's Content Process Limit: By default, Firefox uses multiple processes for performance. You can lower this to restrict its memory use:Type about:config in the Firefox address bar and press Enter.Accept the warning.Search for dom.ipc.processCount.Double-click it and change the value to 1 or 2. This forces Firefox to use fewer system resources. [1] (https://en.wikipedia.org/wiki/Firefox)Enable Memory Minimization: If the browser starts slowing down, type about:memory in the address bar and click the Minimize memory usage button under the Free memory section.Use a Tab Suspender Extension: Install a lightweight add-on like Auto Tab Discard from the Firefox Add-ons store. It mimics Chrome's behavior by automatically putting background tabs to sleep.Turn Off Hardware Acceleration: Sometimes, your computer's integrated graphics conflict with Firefox under low memory conditions. Go to Firefox Settings > type "hardware" in the search box > uncheck Use recommended performance settings > uncheck Use hardware acceleration when available. [1] (https://www.reddit.com/r/firefox/comments/1pp9z79/firefox_using_massive_amounts_of_ram_and_slowing/), [2] (https://www.youtube.com/watch?v=EtXt_jw2tww). This Method I tried, but did not work-Firefox to use fewer system resources. Can you suggest how to reduce or minimize its memory footprint?

Upgraded to Firefox V.155.0 (64bit). Using Windows 11. The old version when accessing my Bookmarks allowed the option with a right mouse click to open that bookmark with the option "Open in New Tab". That option has disappeared. How do I get it back?

Current firefox version: 155.0

Since the last few updates, update frequency of title bar of inactive tabs slows down over time. Sometimes there is important info in title bar that should be updated frequently. Are there any flags in about:config that can be reverted to achieve that?

the build in VPN is not working anymore: the messages we get are often like "no internet connection". i did use it now for some weeks, but after the last update it stopped working now for some days.

when I went to turn on Firefox this evening, the icon was gone and there was no access to Firefox. The only way I could access the internet was through Safari, which I otherwise never use. This happened 2 or 3 weeks ago but, that time, I was able to find the icon. This time that is not the case.

The new VPN feature is really wonderful. But I'll run through my 50gb practically overnight if I leave the feature on and all my YouTube traffic runs through it.

I would like a feature where I can whitelist (or blacklist?) certain websites. Then, my personal browsing on most websites would be protected even if YouTube could get its hooks into me.