Firefox Community Forum

Firefox opens full screen on my main monitor, one of three, but not the last-opened and before resizing to its last-used location and size. This three-stage process happens in a instant, interfering with live activity on my main monitor besides being really annoying. Hasn't always behaved this way. Any suggestions?

Thanks, Mike

Firefox 144.0 64 bit

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.

Hi everyone,

I’ve noticed that Firefox tends to use a lot of memory when I run several browser-based tools at once — especially web calculators or dashboards that update data dynamically.

For example, when I’m testing a lightweight web calculation app (something similar to a gratuity calculator that updates values in real time), Firefox memory usage slowly increases, and sometimes the browser even freezes if multiple tabs are open.

I’ve already tried:

Clearing cache and disabling extensions

Running in Safe Mode

Using hardware acceleration on/off

Still, the problem persists.

So I’d like to ask:

1. Are there any specific settings or flags that can help manage memory usage better for interactive web tools?

2. Does Firefox handle JavaScript-heavy calculations differently compared to Chromium-based browsers?

3. Any recommended performance tweaks for developers testing such tools locally?

Would really appreciate advice from anyone who’s optimized Firefox for this kind of lightweight, web-app testing.

Thanks in advance! 🙏 bold text

Your browser dead ass just doesn't respond when I click on it. I have a new mac mini 4 and have the latest update for firefox. it's absolute dogshit to be honest. I'm lucky if the browser lets me click on anything, eg., bookmarks, add-ons, history are nonfunctional. Also my tabs on the browser get squished together and superimposed such that 2-3 separate tabs appear as though they are one tab. I have never had an issue like this before when using firefox. I don't encounter the issue with safari or chrome, but I don't like those browsers. Do you have insight as to why firefox mozilla is suddently ass?

Running Firefox 140.3.1 ESR on Debian, lately I've been experiencing a bug when I have several instances of Firefox open, and multiple tabs open in each instance. After a few minutes of browsing and opening and closing tabs, I am unable to drag tabs to rearrange them (above the address bar). The "X" that is part of the tab also doesn't work to close the tab, and clicking the main "hamburger" menu icon (three horizontal lines) does not drop down the menu. If I switch to a different instance of Firefox that is already running, sometimes the "hamburger" menu icon starts working (sometimes not), and I am able to exit and restart Firefox, which works for awhile, and then a few minutes later the same thing happens again. Interestingly, when it's not working, I am still able to "right-click" on the tab and choose "close tab" from the drop-down menu.

I've been trying to discern a pattern, but have not been able to find a way to reliably reproduce the error. It often seems to happen when I'm using Reddit or Craigslist (maybe only more noticable because I often open and close a lot of tabs on those two sites). At one point I thought it might be related to opening a new tab for a site that had previously been opened in another Firefox window (instance), but that may be a false lead, because I haven't been able to find a way to consistently trigger the bug.

Thank you for maintaining the best privacy-respecting browser in the world, an indispensable tool for me.

Firefox not responding on macbook M4 Macos Tahoe 26.0 I tried restarting Firefox I tried restarting my macbook But everything repeats. Use Firefox for a while and it freezes again. Tôi sử dụng Firefox mới nhất: 143.0.1

I've seen on this forum from April that people are having an issue with Firefox and Google Passkey. I'm trying to log into my gmail accounts and can't get passkey to work. It freezes the browser and I'm not sure why this hasn't been resolved. Mac updated to Tahoe recently and I was on Sequoia 15.7.x (not sure exactly. Still froze. Photos are to show what's happening and that I needed to Force Quit each time.

As per the topic, since the MacOS 26.0.1 update Firefox freezes after resuming from sleep. Specifically, tab selection, page refreshes or menu selections cannot occur. Keyboard command to quit does work and after a reload all tabs, windows and function is restored

None of my extensions have changed and for the first week or so after the initial MacOS 26 release this issue wasn't occurring. No other application or system changes have occurred since 26.0.1.

I've uninstalled every profile and installation of firefox. All addons are gone.

Upon reinstalling regular firefox, doing refresh, and syncing my account, the browser immediately freezes.

This issue has started within the past week. I've not done any major changes to my computer or firefox in general. Edge browser does not have this issue.

about:processes also freezes, making troubleshooting difficult.

I'm currently running firefox without syncing at the moment, but this isn't an ideal long term solution.

Hi, I’ve noticed that Firefox often uses a lot of memory when I have multiple tabs open, even more than Chrome or Edge on the same number of tabs. Sometimes it slows down my system or makes switching between tabs laggy.

Is this normal behavior, or is there a way to reduce Firefox’s RAM usage without losing performance? Are there specific settings, add-ons, or troubleshooting steps I should try?

Thanks in advance!

I use both Firefox and Google Chrome. My mouse works fine with Chrome but with Firefox there are frequent long delays (60-120 sec.) when moving from one web site to another. The mouse just freezes up and I have to struggle to close Firefox. No problem with the mouse with Chrome, but I prefer Firefox and its features. Any suggestions?

Macbook Pro using Tahoe 26.0.1; desktop freezes when Firefox 140.3 is active. Desktop icons do not work. Firefox has to be shutdown for the desktop icons to work.

Hi,

When i switch between two tabs by clicking with my external mouse ( I am on one tab and then point and click on another) and then directly start to scroll the page zoom like it does when i hold ctrl+zoom. What causes this?

It does not do the same in other browsers or other apps. It does the same with external mouse and track pad.

Win 11 Pro Firefox 143.0.3 (64-bit)