How to Speed Up Firefox

This wikiHow teaches you how to speed up the performance of Mozilla Firefox for Windows and macOS.

Method 1
Method 1 of 8:

Updating to the Latest Version

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    Open Firefox on your PC or Mac. You’ll find it in the All Apps area of the Start menu in Windows, and in the Applications folder in macOS.
    • The Firefox developers are always releasing updates to improve the speed of the app. Use this method to make sure you’re using the latest version.
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    Click the ≡ menu. It’s at the top-right corner.
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    Click Help. It’s near the bottom of the menu. This option appears as a ″?″ icon on some versions of Firefox.
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    Click About Firefox. Firefox will now check for an update. If an update is available, you’ll see a button that says ″Update to (version number).″ If you don’t see this button, you’re already using the latest version.
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    Click the Update to button. The update will now download. Once it’s ready to install, the ″Update″ button will change to ″Restart to update Firefox.″
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    Click Restart to update Firefox. Firefox will now shut down to install the update. Once the update is complete, Firefox will restart automatically.
    • You may have to give the install permission to run.
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Method 2
Method 2 of 8:

Freeing Up Memory

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    Open Firefox on your PC or Mac. You’ll find it in the All Apps area of the Start menu in Windows, and in the Applications folder in macOS.
    • This method can help when certain websites or extensions seem to be bogging down Firefox.
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    Type about:memory into the address bar and press ↵ Enter or ⏎ Return. This opens the memory troubleshooting tool.[1]
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    Click Measure in the “Show memory reports” box. If you’re a developer or more advanced user of Firefox, you can use this feature to determine which processes are running and how much memory each process uses. Scroll through the report to view each section.
    • Some add-ons are listed in the memory report by name, but others will only appear as a hex code.[2]
    • If a support representative or developer has requested you run and save a memory report, click Measure and save in the ″Save memory reports″ box, then choose a location to save the report. You can then attach that report to an email or upload it to a bug database if you were asked to do so.[3]
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    Click Minimize memory usage. It’s near the top-right corner of the page. Firefox will now release in-use memory that’s no longer needed. This should provide a pretty quick boost in speed.
    • If memory usage remains high no matter what you do, your computer may not have enough RAM to support the number of tabs and/or windows you have open at the same time. Try browsing with fewer open tabs and windows, and consider upgrading the RAM in your computer.
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Method 3
Method 3 of 8:

Using Safe Mode

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    Open Firefox on your PC or Mac. You’ll find it in the All Apps area of the Start menu in Windows, and in the Applications folder in macOS.
    • When you use Firefox’s Safe Mode, you’ll be starting up a clean version of Firefox that doesn’t use any Add-ons (extensions or themes). If using Firefox is faster when you’re in Safe Mode, the issue is probably with an installed add-on or theme.[4]
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    Click the ≡ menu. It’s at the top-right corner.
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    Click Help. It’s near the bottom of the menu. This option appears as a ″?″ icon on some versions of Firefox.
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    Click Restart with Add-ons Disabled. A confirmation message will appear.
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    Click Restart. A message with information about Safe Mode will appear.
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    Click Start in Safe Mode. Firefox will now launch without extensions and themes.
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    Browse the web. If it’s much faster to use Firefox in Safe Mode, it’s probably because one of your add-ons is acting up.
    • See Disabling Add-ons to learn how to turn these features off. Start by turning all of them off. Then, enable just one add-on and try browsing with it. If browsing is still nice and fast, you can leave that add-on enabled and try another.
    • Keep enabling add-ons until you’ve found the one that’s causing problems.
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Method 4
Method 4 of 8:

Disabling Add-ons

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    Open Firefox on your PC or Mac. You’ll find it in the All Apps area of the Start menu in Windows, and in the Applications folder in macOS.
    • Extensions and themes often slow down your browsing. If you’ve found that Firefox is way faster in Safe Mode, use this method to figure out which extension or theme is the culprit.
    • If you’re an advanced user, you can run a memory report to see how much of your RAM is utilized by certain add-ons.
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    Click the ≡ menu. It’s at the top-right corner.
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    Click Add-ons. It’s near the middle of the menu.
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    Click Extensions. It’s in the left panel.
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    Click Disable next to all options. This turns off each add-on without deleting them.
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    Click Themes. It’s in the left panel.
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    Click Disable next to the active theme. This switches you back to the default Firefox theme.
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    Select one extension or theme to enable. To find the problem add-on, click Enable next to one of the extensions or themes, leaving the rest disabled.
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    Browse the web. If using Firefox is still fast using the one add-on you’ve enabled, that one is probably okay.
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    Enable another add-on. Again, once another add-on is turned on, try browsing again. Repeat these steps until you’ve found out which add-on is slowing you down.
    • If Firefox remains slow no matter which add-ons you’re using, the issue could be with a problematic driver. If the issue only occurs when browsing a certain website, the website itself could be the culprit.
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Method 5
Method 5 of 8:

Clearing the Cache, Cookies, and History

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    Open Firefox on your PC or Mac. You’ll find it in the All Apps area of the Start menu in Windows, and in the Applications folder in macOS.
    • If you’re experiencing slowness, it may be the result of a cached item, bad cookie, or a large web history. Use this method to clear these options.
    • Clearing cookies will log you out from any websites you have open.
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    Click the ≡ menu. It’s at the top-right corner.
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    Click Options. It’s near the middle of the menu.
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    Click Privacy & Security. It’s in the left panel.
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    Scroll down and click Clear Data. It’s under the ″Cookies and Site Data″ header in the right panel.
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    Select the information you want to clear. Check the boxes next to ″Cookies and Site Data″ and ″Cached Web Content″ to select them both. The amount of space occupied by each type of data appears next to its name.
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    Click Clear. A confirmation message will appear.
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    Click Clear Now to confirm. The cache and cookies are now clear.
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    Scroll down and click Clear History. It’s under the ″History″ header.
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    Select the information you want to clear. Choose Everything from the drop-down menu at the top of the screen, and then check all boxes. This ensures that your entire history is cleared, not just the sites you’ve visited most recently.
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    Click Clear Now. Your history is now clear.
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Method 6
Method 6 of 8:

Blocking Trackers and Third-Party Cookies

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    Open Firefox on your PC or Mac. You’ll find it in the All Apps area of the Start menu in Windows, and in the Applications folder in macOS.
    • The same tools that track you as you use the web also slow down your browsing experience. This method teaches you how to block these trackers, which should improve speeds and keep you safer on the web.
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    Click the ≡ menu. It’s at the top-right corner.
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    Click Options. It’s near the middle of the menu.
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    Click Privacy & Security. It’s in the left panel. The ″Content Blocking″ area now appears at the top of the right panel.
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    Check the box next to ″All Detected Trackers.″ You can also choose whether to block trackers in all browser windows (Always) or just when you’re browsing privately.
    • Though you’ll almost definitely see improvement in speed, some websites and tools may not be able to load. You can always return to this screen and re-enable tracking temporarily if you’re running into this issue.
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    Check the box next to ″Third-Party Cookies″ and select Trackers. This prevents third-party cookies from following you around the web.
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    Select an option under ″Send websites a ″Do Not Track″ signal. It’s at the bottom of this section. The best option to select here is Only when Firefox is set to block Detected Trackers.
    • This means as long as you’ve enabled the option in Step 5 (″All Detected Trackers″), you won’t be tracked by any websites—but if you need to turn that feature off for troubleshooting, this one will also turn off automatically.
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    Clear your cookies and cache. Now that you’ve updated your settings, it’s time to clear out what’s collected so far. See this method to learn how.
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Method 7
Method 7 of 8:

Turning Off Hardware Acceleration

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    Open Firefox on your PC or Mac. You’ll find it in the All Apps area of the Start menu in Windows, and in the Applications folder in macOS.
    • If text, photos, videos, and games appear choppy, try this method.
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    Click the ≡ menu. It’s at the top-right corner.
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    Click Options. It’s toward the middle of the menu.[5]
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    Click General. It’s in the left panel.
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    Scroll down to the ″Performance″ section. It’s toward the bottom of the page.
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    Remove the check mark from the “Use recommended performance settings” box. Additional options will appear.
    • If there was no check in this box, just skip to the next step.
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    Remove the check mark from the box next to ″Use hardware acceleration when available.″ The feature is now off, but you’ll still need to restart the browser.
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    Click the ≡ menu and select Exit. It’s at the bottom of the menu.
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    Restart Firefox. Firefox will now launch without hardware acceleration enabled, which may lead to a faster browsing experience.
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Method 8
Method 8 of 8:

Resolving JavaScript Issues

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    Open Firefox on your PC or Mac. You’ll find it in the All Apps area of the Start menu in Windows, and in the Applications folder in macOS.
    • If websites running JavaScript hang your browser or display errors that say ″Warning: Unresponsive Script,″ this method is for you. You can change a Firefox setting that controls the amount of time a script has to run before displaying the pop-up that lets you disable it.[6]
    • To give scripts more time to run before displaying an error, you can increase the value to 20 seconds. Sometimes larger or clunkier scripts need more time to execute in certain environments.
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    Type about:config into the address bar and press ↵ Enter or ⏎ Return. A warning will appear, letting you know that continuing can void your warranty.
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    Click I accept the risk. A list of preferences will appear.
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    Type dom.max_script_run_time into the ″Search″ bar. It’s at the top of the preferences list. Once you’re finished typing, one result will appear.
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    Click dom.max_script_run_time. A pop-up will appear, asking you to enter a value.
    • The default value (usually 10 seconds, but may vary depending on the version) indicates that a script has that many seconds to run before displaying the an error.
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    Enter 20 as the value and click OK. Once you make this change, scripts will have 20 seconds to run before displaying the error message that gives you the opportunity to stop the script.[7]
    • If you want to give scripts less time to run before displaying an error message (useful if your computer isn’t powerful enough to run larger scripts), enter the desired number of seconds (any amount over 0, as 0 means ″indefinite″) instead.
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Community Q&A

  • Question
    I followed the directions, then lost my toolbar and adblocker. What do I do?
    Fyt lol
    Fyt lol
    Community Answer
    Reinstall firefox and try again. Or you can try to reinstall, and remove your adblocker and try again. It should work.
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References

  1. ↑ https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-ram#w_memory-troubleshooting-tools
  2. ↑ https://developer.mozilla.org/en-US/docs/Mozilla/Performance/about:memory
  3. ↑ https://developer.mozilla.org/en-US/docs/Mozilla/Performance/about:memory
  4. ↑ https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems
  5. ↑ https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems
  6. ↑ https://support.mozilla.org/en-US/kb/warning-unresponsive-script
  7. ↑ http://kb.mozillazine.org/Script_busy_or_stopped_responding

About This Article

Nicole Levine, MFA
Written by:
Nicole Levine, MFA
wikiHow Technology Writer
This article was co-authored by wikiHow staff writer, Nicole Levine, MFA. Nicole Levine is a Technology Writer and Editor for wikiHow. She has more than 20 years of experience creating technical documentation and leading support teams at major web hosting and software companies. Nicole also holds an MFA in Creative Writing from Portland State University and teaches composition, fiction-writing, and zine-making at various institutions. This article has been viewed 68,072 times.
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Co-authors: 6
Updated: April 15, 2019
Views: 68,072
Categories: Firefox
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