Firefox Community Forum

Bug Report for Mozilla Team: When you open a Gmail PDF In another window, the zoom setting has a bad response, with much delay, I inform you of this Bug So you can fix it, thank you very much.

Hello! Appreciate the help I could get. It is rather hard to type when the letters are disappearing as I type it out. I will provide screenshots of my issues and hopefully someone could help me out. I just downloaded the browser and have no idea how to fix the issues. The tabs are constantly flickering in different colors. The letter are disappearing or merging together or sometimes written in bold, crossed out, or underlined. It is making it rather hard to use the browser haha, but let me know what else I can provide to help out identify the issue. THANKS!

When I launch Firefox in Troubleshoot Mode and try to open the Settings page (about:preferences) right away, Firefox becomes unresponsive. This issue does not occur when Troubleshoot Mode is off.

I'm using Firefox 140.0.4 on macOS Sequoia 15.5.

https://gist.github.com/ben-j-c/6d15852955d04c9018600d15d4a8a13e

Context: Here is an animation I generate with a program I'm developing. It being an SVG makes it useful to open in a web-browser. In chromium based browsers I have smooth animation, while in firefox I get much worse performance. At larger animations the problem becomes much more apparent. This is the approximately the largest animation that firefox can handle without lagging too much.

Expected: Firefox should have comparable SVG animation performance as chromium.

Hello... So, a couple of weeks ago, there was a 15-hour blackout during a Windows 11 update. I had exited firefox, and was shutting the laptop down, and it asked if I wanted to update and shut down (or other options). I chose update and close. When the lights came on and the router booted back up, Windows finished updating. It works, but here is the rub: whenever Ffox runs, a couple of minutes into the sessions, it will start displaying previous session screens, screen saver-like: one after the other every ten seconds or so. I can't X out, because it disappears whenever I move the cursor. The images appear not only on Ffox, but cover whatever other app's screen until I move the cursor, which is irritating when you're trying to meet the deadline on a novel! Please help! I am running version 140, by the way.

If a page is maximized I can not move it - I have to click on the 'intermediate' of the three choices (minimize, intermediate, maximize) before I can move it or resize it.

I have three monitors. It's the same behavior on all three.

For some reason my Firefox has started to become much slower when I view / watch anything in full screen, it doesn't matter from where. A Twitch stream in full screen? The Video Player becomes slow, even using the escape key to leave fullscreen takes a bit. Youtube video in fullscreen? Same thing happens. No matter what site is being used, if I go full screen on any video player, everything becomes suuuper laggy. I've tested other browsers and they don't seem to have that issue so it's not a hardware or connection issue.

help me to use the browser!

I just simply need it to maximize.

I'm not too tech savvy. The only thing I tried was to reinstall Firefox which did not help.

About two weeks ago, Firefox started randomly hanging and would stop responding. It wouldn't let me close the program and I always have to restart my system to resolve the problem. Sometimes it only takes a few minutes after restart before it hangs, other times it will be fine for hours.

I've tried multiple solutions I've found online, carefully following instructions: clearing cookies and cache, disabling all extensions, refreshing firefox, creating a new profile, deleting specific files within the Profiles folder, etc.

I've yet to make it more than four hours without the program hanging.

Any assistance or suggestions are greatly appreciated.

I've recently swapped to Firefox from Chrome and I've noticed a huge hindrance.

I use a chatroom website and when I swap to the tab and begin to type, the first letter is randomly eaten/won't be entered into the text field.

For instance I was typing the word "What" and the text field only displayed "hat". Or when typing "Either" only "ither" appeared.

I thought this may have been related to a hardware acceleration issue but both settings did not work. So I started to look at Hotkeys but none of them should be interfering.

Some others have stated they have this issue too and I've been unable to find any solution. Any help?

Greetings...

I have noticed in my Windows 10 Task Manager that Firefox has an excessive number of processes active when Firefox is started with only one empty tab. By excessive, I found eleven (11) Firefox processes today, and I have yet to even start using Firefox.

I have only a simple Theme enabled and no Extensions enabled in my Firefox. I have tried deselection of the "Use recommended performance settings" but this does not appear to help. Disablement of my Theme increased the number of Firefox processes.

Any idea how I can significantly reduce the number of Firefox processes that appear in my Task Manager when I use Firefox? I really prefer to use Firefox as my go-to web browser, but lately it has become troublesome at times.

Thank you in advance for your help with the above problem. Take care...

...ted

been having issues with files lately. i can dl a file and open the folder. if i try to open the file from the browser or the folder directly, the browser window will freeze. additional browser windows are still functional. how do i fix this? no files will open even in safe mode.

when i open firefox (including opening a new tab) my CPU peaks at 100% on all cores for a few seconds. this is without any pages loading and without many heavy extensions (all i have is malwarebytes and dashlane)

When opening Firefox, the screen turns white before page opens! There is a version that was updated for this issue however,at that time I did not have this issue! After downloading the newer version, I now have this white light issue! I like to mention, my computer never crashed! I believe (134.0.3), was the update that was a fix for the White Screen problem. And, I am using ver-139.0.4 (64 bit) (win. 10-64 bit) I appreciate any help with this issue! Thank you!!! geo (7/6/2025)

When debug threejs in firefox(windows, not verified in linux), after breakpoint is hit the other web page is un-operational, you can not click the url on other webpage.

Since the last update Firefox sends the processor load through the roof. Both on desktop and on Android. For the first time since like version 7 I'm a bit disappointed.

What's up with this?

Firefox occasionally stalls during a page load or refresh. A quit/start sequence of Firefox resolves the stall without further action. Is there a key sequence that invokes a restart: Firefox 140.0.2 (aarch64), MacOS 15.5 (24F74)