Firefox Community Forum

Gmail is slower than frozen molasses, it is taking 15 to 20 seconds to respond to mouse clicks and typing as well as scrolling, it takes me more than half an hour to do what should take a few minutes, if this is not fixed soon that will be the end of Firefox for me, I will use Opera instead.

Since a while, I think it is since I created an extra testprofile with "firefox-esr -P", but I've set my main profile as default again

When opening a link in another program than firefox I get always: a popup "Close Firefox" "Firefox is already running, but is not responding. To use Firefox, you must first close the existing Firefox process, restart your device, or use a different profile."

I do have both firefox and firefox esr, I usually use regular firefox the second came with the debian 13 repository.

I keep the esr to test display issues for reproducibility on my personal desktop, because I manage debian 13 kiosk-style desktops with firefox-esr.

(I noticed also that the regular firefox profiles can not be opened in firefox esr, so I use an extra profile for esr)

https://www.mlb.com/gameday/braves-vs-nationals/2025/09/17/776286/live

this site at mlb.com or any site showing a live game eventually freezes up and cannot be closed normally. task manager or re-boot is only way out, starting over with a new instance of firefox after ending all firefoxes.

this has been happening just this past few days, after firefox updated to 143.0 on windows 11 using defender, no other screwed up security software.

firefox needs to fix this, it is not likely anything with the site but rather with firefox latest update, as this has always worked before on this same computer.

Dennis Coleman

Hello,

I have several PC;s but all suffer on occasion absurdly slow performance when a Firefox update is released.

I may be wrong but it appears there are too many of these processes running, I tried changing the value in " about:config " but Firefox defaults the value back to " 12 " when the browser is restarted.

" app.normandy.migrationsApplied 12 "

The below details are from a small, new cube pc that runs great, it is slow but does perform well, even previously just the other day running multiple Live Youtube streams with no issues, until now. :)

Any help would be great. Thank you!!!

" Firefox 142.0.1 (64-bit) "

Device Name Garage Processor Intel(R) Celeron(R) N4020 CPU @ 1.10GHz 1.10 GHz Installed RAM 4.00 GB (3.83 GB usable) Storage 58 GB SSD VID:32 MMC64G Graphics Card Intel(R) UHD Graphics 600 (128 MB) Device ID C12EB49A-0C22-41C3-A8E6-4420E4A419B0 Product ID 00330-50441-82637-AAOEM System Type 64-bit operating system, x64-based processor Pen and touch No pen or touch input is available for this display

После включения ПК бывает, что я не могу ввести текст в браузере.(как буд-то включается режим только для чтения, что не позволяет текст ввести). горячие клавиши работают, но текст не вводиться только в браузере. Оно само по себе проходит. Как это исправить?

when i open firefox and have one tab open, doesnt matter what site it will freeze and i go to task manager and it says i have 15 open and ill end task and open again and it will say more or less

Description: We have encountered a significant performance issue with NativeMessaging API in Firefox when an extension communicates with a native application.

In scenarios where many objects must be enumerated (e.g., ~458 certificates), Firefox is dozens of times slower than Chromium-based browsers.

Environment:

Firefox (latest stable, reproduced in 2025)

Windows 11 x64

Same machine and same native plugin tested in Chrome, Edge, Yandex Browser

Steps to Reproduce:

Create a WebExtension that communicates with a native application via NativeMessaging.

Perform enumeration of a large number of objects (≈ 450–500).

Measure execution time in Firefox vs Chromium.

Actual results:

Firefox: enumeration of 458 objects takes ~2 min 30 sec

Chromium/Edge/Yandex Browser: enumeration of the same 458 objects takes ~5 sec

Additional tests: Round-trip time (RTT) for a single message:

Firefox: ~73.7 ms

Chromium: ~0.3 ms

Because the extension and the plugin exchange a large number of messages, this performance gap becomes critical.

Expected results: NativeMessaging API in Firefox should perform at a level comparable to Chromium browsers, so that extensions relying on heavy message exchange remain usable.

References: Bug 1288912 – Native messaging performance is extremely poor

Although this bug is marked as resolved, performance testing still shows a major discrepancy in the current versions of Firefox.

Question: Is there any ongoing work or plan to optimize the implementation of NativeMessaging API in Firefox to address this performance issue?

I'm listening music from youtube and playing Guild Wars 2 in the same time. Tell me pls bc I think it's unnormal, why I see in task manager that Firefox is opened 12-17 times?...

Добрый день! Обратил внимание, что с последним обновлением. у меня стала виснуть браузерная строка полностью и я не могу зайти в настройка. Уже было несколько раз так и мне помогает только полный перезапуск браузера.

Я могу прислать видео, как это выглядит.

Прошу помочь решить эту проблему. Спасибо

I often keep many tabs open for research, and Firefox memory usage grows significantly over time. Are there practical settings or habits that help manage memory without sacrificing usability?

I run a drafting site where we share shop drawings for contractors and architects: https://usadraftsman.com

Whenever I open these drawing preview pages in Firefox, the browser gets slow or sometimes becomes unresponsive. The same pages load completely fine in Chrome, so I’m trying to understand what might be causing this only in Firefox.

Most of the previews are large drawings or viewer embeds, so maybe Firefox is struggling with rendering them. I tried clearing cache and turning off extensions, but the issue still comes back.

If anyone has dealt with similar heavy graphics or rendering issues in Firefox, what should I check or adjust? Any suggestions would be appreciated.

Hello Firefox Support,

Since the latest update of the Firefox browser, I have been experiencing frequent freezes. The browser becomes unresponsive when performing basic actions such as:

• Clicking on the menu

• Closing tabs

• Copying or editing the URL

When this happens, the only way to recover is to close Firefox and reopen it.

Could you please advise on how to resolve this issue?

Thank you for your support.

Best regards, Mohamed Adel

Ever since this month's Windows 10 update I've been having problems with Firefox. I start it, the menu bar and tab comes up, but then nothing. I can't access any web sites. I tried removing the Windows update, then tried uninstalling and reinstalling Firefox, and then messing with the settings. In each case Firefox would work for a couple of days, then I'd have to start it three or four times to get it to work, then it wouldn't work at all. I've been using it for 10 or more years now (four on this computer) and have never had any problems before. I'm loathe to switch to another browser, but if this can't be fixed I won't have any choice. This is what happens when I start the program.