FIX: Mozilla Firefox memory leak in Windows 10

Ivan Jenic
by Ivan Jenic
Troubleshooting Expert
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  • Firefox is a great browser, but even great browsers suffer from issues.
  • Speaking of Firefox errors, many users reported memory leaks in Firefox.
  • To fix this issue, make sure that Firefox is up to date and disable all addons.
  • Want to learn more about Firefox? Be sure to check our Firefox hub for more information.
firefox minimize memory usage

Firefox is one of the most popular browsers today, but even this stable, user-friendly browser could cause some problems.

After some time, Firefox could start to take more memory than it should, but we’ll tell you how to solve this problem.

What do I do if Firefox uses too much memory?

6 solutions to fix Firefox high memory usage in Windows 10

  1. Update your browser
  2. Disable your plugins
  3. Check Firefox preferences
  4. Enable Hardware Acceleration
  5. Use fewer tabs
  6. Use the ‘Minimize memory usage’ button

1. Update your browser

mozilla firefox windows 10

First, make sure that your Firefox is up-to-date, because newer versions of the browser usually take less memory. To download the latest Firefox version, go to Mozilla’s official website.

2. Disable your plugins

You can also disable or delete some unnecessary plugins and add-ons, because they also could use a lot of memory.

Actually, disabling unnecessary add-ons and plugins proved to be the best memory saver option. Of course, if it turns out that you need some of the disabled add-ons, you can always re-enable it.

— RELATED: Fix: Keyboard not working in Firefox

3. Check Firefox preferences

But if your browser is updated, and you run only necessary plugins and add-ons, you’ll have to do a couple of tweaks in order to solve the memory leak problem. Here’s what you should do:

  1. Type about:config in Mozilla Firefox bar and adjust the following preferences (by double-clicking on them) to enhance your memory:
    • browser.cache.memory.capacity (set to 0)
    • browser.cache.memory.enable (set to false)
    • browser.sessionhistory.max_total_viewers (set to 0)
    • browser.tabs.animate (disable)
    • browser.sessionstore.max_concurrent_tabs (set to 0)
  2. Now, edit the following preferences to boost the loading speed:
    • (set to true)
    • javascript.options.jit.content (set to true)
    • content.notify.backoffcount (set to 5)
    • network.dns.disableIPv6 (set to true)
    • network.http.pipelining (set to true)
    • network.http.proxy.pipelining (set to true)
    • network.http.pipelining.maxrequests (set to 8)
    • plugin.expose_full_path  (set to true)
    • ui.submenuDelay  (set to 0)

4. Enable Hardware acceleration

  1. Launch a page that plays Flash video > right-click on the video player > go to Settings to open the Adobe Flash Player.
  2. Open the Display panel.
  3. Make sure to check the Enable hardware acceleration option.
  4. Close your browser and launch it again.

— RELATED: Full Fix: Firefox install stuck in Windows 10, 8.1, 7

5. Use fewer tabs

Most Firefox users open only a few browsers at the same time. However, if you have around 100 tabs open at once, this may affect your memory. Try to close the tabs that you’re not using actively.

6. Use the Minimize memory usage button

  1. Open Mozilla Firefox Browser
  2. In the Address Bar type in about:memory
  3. Under the Free Memory tab, click on Minimize memory usage
  4. Restart your browser

As simple as it looks, this method works. Don’t forget to always update your version of the browser you are using.

Mozilla Firefox Quantum is now available to try, a newer and a faster version than ever before. If you want to download it, here’s a link.

You also should know that the more powerful computer you have, the more memory Firefox will use.

So you shouldn’t think that you’ll surely avoid memory leaking problems with Firefox if you have more memory in your computer.

That would be all, if you have any suggestions, comments or maybe other solutions of this problem, we would like to read your thoughts in the comments section below.

FAQ: Learn more about Mozilla Firefox

  • How do I fix memory leak in Firefox?

To fix memory leaks in Firefox, be sure to update your browser and disable all addons. In addition, try opening fewer tabs.

  • Why is Firefox using so much RAM?

If Firefox is using too much RAM, that can be due to the number of open tabs or due to certain extension that is working in the background.

  • Does Firefox drain battery?

Yes, Firefox drains the battery, and it will drain more of your battery if you have multiple tabs open or if you’re running resource-intensive extensions.

  • How do I optimize Firefox?

To optimize Firefox, make sure that you’re not having dozens of tabs open. Also, disable or remove any extensions that you don’t use actively.

Editor’s Note: This post was originally published in April 2015 and has been since revamped and updated in April 2020 for freshness, accuracy, and comprehensiveness.