Firefox Community Forum

Tor browser 14.5.8 (based on Mozilla Firefox 128.14.0esr) LibreWolf 143.0.3-1 Each uses 100% of a CPU thread on Linux Debian 13 (Trixie) with KDE, while internet is not accessible for hours. I have tried to open new empty tab and close single website tab in Tor browser, but that did not decrease the load. Firefox 140.3.1esr also uses around 100% when i count up all its CPU threads load.

Can anyone reproduce this? Maybe the browser needs to run for some time so the issue is reproducible. If you have idea what to try (i will not use different Firefox version), let me know exact steps.

Hello,

we are currently experiencing high memory usage issues with Firefox on our terminal servers.

Problem description: All employees work within a terminal server environment. When using web applications such as Vimcar (https://fleet.vimcar.com) in Firefox, we observe a very high RAM consumption. A single Firefox tab can consume 2 GB of RAM or more after being open for several hours. As a result, the terminal server becomes slow or unresponsive, and other users on the same server are affected. Since the terminal server allocates resources on demand, a hanging process continues to request memory until it eventually terminates itself, which severely impacts overall system performance.

Questions: 1. Are there settings or configuration options to reduce Firefox’s memory usage in terminal server environments? 2. Are there recommended best practices for running Firefox with memory-intensive web applications on terminal servers? 3. Is it possible to set memory limits per tab or per user session to improve stability?

Thank you very much for your assistance.

When I have Firefox and a word document open in my mini mac the Firefox application image is suddenly pushing out or sight any word document I also have open at the same time. Conversely, when I relocate the word document and seek to open it again Firefox gets pushed out. What is going on and how do I stop it?

I am not experiencing this problem when I have Safari and a word document simultaneously opened.

fred 10/14/25 at 1:20 pm PST [email removed]@gmail.com

The NY Times home page has taken to​ animating many of their illustrations. I would like to prevent that; they​ sometimes cause Firefox on my Windows 11 system to freeze for​ periods of varying length, and I simply don't want them. Their helpbot suggested restarting FF and clearing the cache, both​ proved useless. Changing the setting in Firefox to block audio & video has no​ apparent effect. Videos still play from the NYT page and the browser​ still freezes. Is there a way?

firefox is not displaying all characters on a page. Then, the missing characters suddenly get filled in. I have disabled all extensions thinking that is the probable problem, and it seems to work short term. But then it start up again. Have to reload a page, and sometimes THAT doesn't even work. Yesterday, I removed and reinstalled firefox. It was OK for about 1 hour, but now the problem is back. It only seems to be firefox (default browser). Now, hope this helps. I just got an email (Thunderbird) with no content except for a black block then appears and disappears. Have you ever heard of these things happening? P.S. As I type this, characters are starting to disappear....Oh! There back now. Chrome does not seem to have this issue, but I rarely us it (browser of last resort). Microsoft edge browser started intruding about 3 months ago. Comes up as my default browser? (I do not load it ever!). Things are getting really screwy. Hope you can help. P.S.S. as I get ready to send this to you, about 25% of what I have typed is no longer showing.

My internet browsing gradually gets slower over time. By the end of a day or a couple of days, it is unusable. The problem isn't bandwidth. A speed test shows that throughput is absolutely normal. It's the browser response to navigation. ie clicking a link, typing a URL into address bar, etc. and having to wait minutes for the page to start loading.

If I quit the browser and re-open, everything goes back to normal.

Any ideas what might be the problem?

On Windows 11 laptops, I am currently using an Acer Nitro w/ 12th gen Intel i5 16GB RAM, I use my touch pad for scrolling on sites with infinite scrolling. Occasionally this function breaks, when it does it breaks for every tab in the browser window including the setting, I haven't found a singular or specific cause yet. I have troubleshooted it in the community, the prevailing logic being that themes or extensions are causing some incompatibility, so I have reset everything to defaults and made sure I have no extensions loaded, and the problem persists. I can temporarily fix the issue by going into my settings and turning hardware acceleration on and off again. I am writing this to hopefully point out this bug as clearly as possible in hopes that your programmers can fix it in a future update, as repeatedly turning a setting on and off to "fix" it might not be the best solution in the long term.