If your typing is delayed in Firefox, try turning off hardware acceleration first. Open the menu, choose Settings, select Tabs and browsing, uncheck Use recommended performance settings, uncheck Use hardware acceleration when available, then exit and restart Firefox. Mozilla says some graphics processors and driver setups can cause trouble showing text when hardware acceleration is on.
These steps follow Mozilla’s support articles on troubleshooting extensions, themes, and hardware acceleration, quick fixes when Firefox slows down, high memory or CPU use, and Refresh Firefox. Work through them in order and test your typing after each one.
Start With Troubleshoot Mode
Mozilla’s Troubleshoot Mode temporarily disables all extensions, uses the default theme, and turns off hardware acceleration, so it’s a quick way to find the cause. Click the menu button, click Help and Report, select Troubleshoot Mode…, and click Restart, then click Open. You can also hold Shift while starting Firefox.
Result: If typing is normal in Troubleshoot Mode, Mozilla says an extension, theme, or hardware acceleration is the likely cause; use the sections below to find which. If the delay continues in Troubleshoot Mode, those aren’t the cause, and changed Firefox preferences or something outside Firefox may be. Don’t click Refresh Firefox in that window unless you mean to reset Firefox.
How to Turn Off Hardware Acceleration in Firefox
- Click the menu button (three horizontal lines) and select Settings.
- Select the Tabs and browsing panel on the left.
- Under Performance, uncheck Use recommended performance settings. An additional setting appears.
- Uncheck Use hardware acceleration when available.
- Click the menu button and select Exit.
- Start Firefox the way you normally do and test your typing.
Result: If the delay is gone, hardware acceleration was likely the cause. Mozilla says you can keep it off, or update your graphics drivers and try turning it back on.
How to Check Your Theme and Extensions
- To rule out a theme, click the menu button, click Extensions and themes, select Themes, and enable the System theme.
- To rule out extensions, select Extensions and turn off the toggle for each enabled extension.
- Exit and restart Firefox, then test your typing.
- If typing is fixed, turn extensions back on one at a time (restarting each time) until the delay returns.
Result: You find the extension or theme causing the lag. Mozilla suggests that if you have many extensions, turning on half at a time takes fewer restarts. Disable or remove the bad one, check whether it has an update, and turn the others back on.
Other Fixes to Try
- Update Firefox. Mozilla says the latest version contains fixes for many problems that could slow Firefox down. See our guide to Firefox updates.
- Find a resource-hungry tab. Open the Firefox Task Manager by typing about:processes in the address bar, then close tabs that use a lot of memory or CPU.
- Use fewer tabs and close other apps. Mozilla lists both as ways to free up resources.
- Restart Firefox and your computer. Mozilla notes long sessions can build up resource use.
Last Resort: Refresh Firefox
Refresh Firefox restores Firefox to its default state while keeping your bookmarks, history, passwords, cookies, autofill information, and personal dictionary. It removes extensions and themes, website permissions, modified preferences, added search engines, and toolbar customizations. Afterward, you can restore the menu bar and toolbars in Firefox if you had them turned on. To use it, open Help and Report > More troubleshooting information and click Refresh Firefox.
Frequently Asked Questions
Is it bad to leave hardware acceleration off?
Mozilla says you can simply run without it if it fixes your problem. If you’re seeing high CPU use instead of display problems, Mozilla’s performance article actually suggests keeping hardware acceleration on, so test both. If the same delay shows up in another browser, you can also turn off hardware acceleration in Google Chrome. Other apps have the same kind of switch; for example, you can turn hardware acceleration on or off in Spotify when its desktop window lags.
What if the delay continues in Troubleshoot Mode?
Mozilla says that if the problem persists in Troubleshoot Mode, it isn’t caused by an extension, theme, or hardware acceleration. Other possible causes include changed Firefox preferences, which Troubleshoot Mode doesn’t disable. Mozilla also suggests scanning your computer for malware when slowness isn’t explained by anything else.
More Firefox Guides
Matthew Burleigh is the founder, head writer, and editor of Solve Your Tech, which he launched in 2012. He has written technology tutorials since 2008 and worked in IT since 2003, including small-business support, IT management, and consulting. He holds Bachelor’s and Master’s degrees in Computer Science from Arizona State University.
Matthew writes practical guides for Windows, iPhone and iPad, Microsoft Office, Outlook, Google apps, and Android. Solve Your Tech’s guides are tested on current devices or checked against official product documentation, with clear steps, sources, and update dates.
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