Firefox Community Forum

Hi everyone,

I run a construction estimating construction estimating website where we share project-based cost estimates and detailed breakdown for contractors, architects

I’ve noticed a weird issue in Firefox lately.

Some of the heavier pages (especially ones with large tables, detailed breakdowns, and embedded content) start getting really slow or sometimes even become unresponsive in Firefox. The same pages load completely fine and smooth in Chrome, so I’m trying to understand what Firefox might be struggling with specifically.

I already tried the basic stuff like clearing cache, testing in private mode, and disabling extensions, but the issue still keeps coming back.

It seems more noticeable on pages with a lot of structured data and embedded elements, so I’m wondering if it could be a rendering, memory, or layout issue on Firefox’s side.

Has anyone dealt with similar performance issues on Firefox with data-heavy or content-heavy web pages?

What should I look into next — layout structure, CSS rendering, JS execution, or something Firefox-specific I might be missing?

Any guidance or debugging tips would be really appreciated.

I have been using Firefox forever. It has been running very slow and bugging out especially with you tube on close. I've been working on this for a couple of weeks and am about to give up. My self built system is about 10 months old. Am using a completely debloated MS 11 pro 25h2. Did not ask for AI from Firefox and have disabled AI in Firefox and copilot is long gone. I have tried everything. Am about to quit firefox. Have refreshed firefox and prevented firefox from running in MS win 11 pro "efficiency mode". I usually have to exit firefox with task manager - there are usually 17 instances of firefox running. Mozilla has become Microsoft.

The system: Gigabyte B650 mobo, 32 gig of DDR5 6000, AMD 7700X processor and an Asrock 9060 graphics card with 16 gig DDR6 Vram. All other apps are running just fine. So I don't think a lack of compute is the problem.

Help please! Thanks in advance!

When i start fire fox it immediately opens 10 additional versions in the background which I can see in task manager and they take up a lot off memory. If i end task them they immediately come back. This only started recently. I noticed it because now when i open say a youtube video it shows it as number 4. This never happened before unless I had the same video open more than once.

If I can not stop this I will have to uninstall.

Estoy observando un comportamiento específico en Firefox que no logro reproducir en otros navegadores basados en Chromium.

Escenario de prueba:

Sitio web con un visor panorámico personalizado. Imágenes panorámicas de aproximadamente 4.500 px de ancho. Movimiento horizontal continuo y lento. Sin reproducción de video ni elementos pesados adicionales.

Resultados observados:

En Chrome, Edge, Brave y Opera el desplazamiento es fluido desde el primer instante. En Firefox el desplazamiento comienza con pequeños tirones o saltos visibles. Los tirones disminuyen progresivamente y desaparecen después de aproximadamente 4 a 12 segundos, dependiendo de la cantidad de panorámicas activas. Una vez estabilizado, el movimiento es completamente fluido. El comportamiento se reproduce incluso utilizando una sola imagen panorámica. Si existen varias panorámicas, el síntoma vuelve a aparecer cada vez que una nueva imagen entra en pantalla.

Pruebas realizadas:

Se descartó que el problema estuviera relacionado con transiciones entre imágenes. Se descartó que estuviera relacionado con programación o temporizadores. Se probó con una sola imagen activa. Se probó utilizando distintos métodos de desplazamiento. El comportamiento sigue siendo exclusivo de Firefox.

La impresión es que Firefox requiere algunos segundos para estabilizar el renderizado o la decodificación de imágenes panorámicas anchas antes de alcanzar una animación completamente fluida.

¿Existe alguna recomendación específica para animaciones panorámicas continuas de gran ancho en Firefox?

Is anyone looking into this? I found an article that told me to remove some cash files and it seemed to fix the issue but it continues to reoccur. Some apps such as MS360 Outlook seem to trigger it, but if it was truly just a corrupt cache issue then cleaning the cash/profile once should have fixed the issue. Instead its become a constant pain in the *** and I'm tempted to find another browser. Seems very recent as well as I've never had issues with firefox before.

Ubuntu 24 Mozilla Firefox 151.0.3

Been using Firefox for over a decade. But lately is has become so slow now. Often freezes up if more than two tabs are open or a website is in any way very complex. What settings and issues should I check? What has changed? I can run the same sites on Brave and Edge browsers with no issues or not nearly as slow and bogged down.

Windows 10 Open Firefox (151.0.2) Google "does alton towers still run in the rain"

My CPU then goes to 100% continuously. Why, CPU occupancy has only gone up in the last few weeks. This happens in a lot of searches.

On a random basis, sites like msn.com, yahoo mail or outlook.com will freeze. Sometimes they may suddenly come back to life, but the normal fix is delete tab and restart tab. Long videos may also freeze. Have cleared history, and changed optimization setting but nothing helps. On 151.0.2 64 bit.

Hi whenever I use my Google account to sign into websites (Google, ebay, YouTube, & anyother sites,) Firefox will become unresponsive, the window containing the tab i was using becomes unresponsive, sort of. - I can't click any open Firefox Tabs, - the red 'Close' radio button is greyed-out, so I can't close any tabs or the window - right-click is unresponsive, so i can't close tabs that way, but Command-W closes the tabs normally, but the others are still unresponsive.

- i can open a new Firefox window (with &/or without Tabs,) which works normally.

- & unrelated, but earlier, Firefox was running really slowly, Youtube videos were slowed down, but audio was normal, and scrolling was slow.

just agreed to the new update for firefox and now my scroll bars will not work properly. they keep jumping to the far right hand side of page and when moving the scroll bar to the left so I can view the whole thing it will not stay. it jumps back to the right side.

I am having a problem with Firefox on Linux Mint. Firefox has completely stopped responding. Even the buttons like close, back, refresh, or menu do not work. The whole browser has become frozen. Shutting down or restarting the system doesn't work.

Firefox version: Mozilla Firefox 151.0 My system: https://termbin.com/s387