How to Speed Up Firefox: 10 Tweaks That Work in 2026

In 2004 the popular way to speed up Firefox was editing about:config to turn on HTTP pipelining and cut the initial paint delay. Those tweaks no longer apply: Firefox removed pipelining years ago and modern versions are tuned for speed out of the box. If Firefox feels slow in 2026, these fixes actually help.

Quick answer: Update Firefox, disable or remove extensions you don’t need, open about:processes to find tabs or add-ons using lots of CPU or memory, and turn hardware acceleration on (or off if you see glitches). If it’s still slow, use Refresh Firefox from about:support, which keeps bookmarks and passwords but resets settings and add-ons.

10 ways to speed up Firefox

1. Update Firefox: Menu > Help > About Firefox.
2. Remove slow extensions: open about:addons and disable add-ons one at a time to find the culprit.
3. Check about:processes: shows CPU and memory for each tab and extension; close heavy ones.
4. Hardware acceleration: Settings > General > Performance. Untick “Use recommended performance settings” to toggle it and test.
5. Clear cache and site data: Settings > Privacy & Security > Cookies and Site Data > Clear Data.
6. Use tab unloading: Firefox unloads background tabs when memory runs low; keeping fewer tabs open helps.
7. Keep Enhanced Tracking Protection on: blocking trackers makes many pages load faster.
8. Refresh Firefox: about:support > Refresh Firefox resets settings while keeping essentials.
9. Try Troubleshoot Mode: Help > Troubleshoot Mode starts Firefox without add-ons and themes to test speed.
10. Check your computer: low RAM, a full disk or malware slow every browser. See how to speed up Windows 11.

Old about:config tweaks to skip

• network.http.pipelining: removed from Firefox; HTTP/2 and HTTP/3 do this better.
• nglayout.initialpaint.delay: no meaningful gain on modern Firefox.
• Random memory and cache “boosters”: can cause instability.

More Firefox tips: make Firefox work like Chrome and the best Firefox add-ons for power browsing. Mozilla’s own high memory and CPU guide has more fixes.

FAQ

Why is Firefox using so much memory?

Usually many open tabs or a heavy extension. Check about:processes.

Does Refresh Firefox delete bookmarks?

No. It keeps bookmarks, history, passwords and cookies, but removes extensions and custom settings.

Is Firefox slower than Chrome?

Speeds are close in 2026; differences depend more on extensions and the sites you use.