It’s a common problem among Firefox power users: you’ve been surfing the web for some time and all of a sudden Firefox’s memory footprint goes through the roof. And although Mozilla’s developers do their best to ensure that Firefox is stable, many people play a part in the browser’s memory leaks without knowing it. So how do you get Firefox to run smoothly again?

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Do you really need that Firefox extension? In my opinion, Firefox’s support for add-ons is one of its most valuable features, but there’s a catch: the longer Firefox has been installed on your hard drive, the more extensions you install and the slower Firefox becomes. That’s why it’s not a bad idea to uninstall extensions you don’t use. If you want to keep a certain extension around just in case, disable it to prevent it from being loaded on startup.

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Disable all unnecessary plugins Aside from your extensions, there are some hidden memory eaters in Firefox that you may want to get rid off: plug-ins you didn’t even ask for. Common plug-ins you might want to disable of include Microsoft Silverlight, Java, Google Update, QuickTime, RealPlayer and Adobe Reader. If you disable the latter, you won’t be able to view PDFs in your browser. Instead, you’ll be prompted with the standard download dialog. Unlike extensions, plugins can be disabled/enabled without restarting your browser.

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Reboot Firefox with a hotkey while saving your tabs Rebooting Firefox is one of the most effective ways to lower its memory footprint. Originally intended for use by extension developers, QuickRestart does just that. Just press Ctrl+Alt+R to reboot Firefox while conserving your currently opened tabs.

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Use Safe mode Vista Rewired suggests using Firefox’s Safe mode in situations where you just need the basic browser. In Safe mode, all your extensions are disabled. You can find a shortcut to Firefox’s Safe mode in its Start Menu folder. Alternatively, you can launch it with the -safe-mode parameter. Visit Vista Rewired here for more details.

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Hack: save Firefox’s state on your hard drive when minimized In 2006, Ryan wrote about a way to have Firefox save its state on your hard drive when it’s minimized. This involves creating a setting of the boolean type in Firefox named config.trim_on_minimize with value true. Although this might free up some memory when Firefox is minimized, it may cause a slight delay when you restore Firefox’s main window. If you want to activate this hack, check out the how-to here.

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Start with a clean slate For that extra speed boost, you should consider starting out with a clean Firefox install. To do this, you’ll need to delete your entire profile folder. If you’re not sure where to find this folder, you might want to read Mozilla’s explanation here. Unless you don’t mind your bookmarks being wiped, ensure that they are backed up. Also note that this will not only delete your bookmarks, but also your extensions, your settings, your saved passwords, your history and so on. That’s a lot of data you’re throwing away, but obviously that’s the reason why wiping your profile is so effective.