I am searching for what the "Don't load tabs until selected" options promises in Firefox.

As it seems the option works fine when Firefox is set to load the tabs from the last session upon start. Only the foreground tab is loaded and all other tabs are only loaded when I select them. For all other cases background tabs are always loaded straight away. (Scenarios tested: load diverted tabs in background, open multiple bookmarks my middle-click on a folder)

What I want is a setting, plug-in or greasemonkey script that prevents every tab that is opened in the background from loading.

OR even better: if there is only one backgrund tab opened -> load it, if there are multiple tabs opened in background within a short amount of time -> prevent loading.


My question is just slightly related to this one: Prevent auto-loading of tabs in Firefox when starting browser They search for something that works at start, but this is already achieved by the "Don't load tabs until selected" option.

Update 2022:
None of the below solutions (provided in 2016) work anymore. Is there currently (in the year 2022) any way to "prevent background tabs from loading in Firefox" ?

  • The UnloadTab add-on can prevent tabs from loading in background, but it doesn't seem to do so when opening multiple bookmarks.
    – and31415
    Apr 14, 2014 at 19:37
  • 2
    There used to be an addon called "BarTab" that did this. Another addon, that I found more useful for my style, because there was no pause time when switching to a new tab, was "Load Tabs Progressively". It allowed you to load, say 3 actively until 8 tabs were loaded in the background (you could customize to say 2 and 21). I upgraded FF last month and lost these addons. I am considering downgrading just for this addon alone... Maybe someone will redo them.
    – BillyNair
    Dec 7, 2014 at 8:17
  • This plugin sounds great. I hope they update it to work with newer FF versions.
    – masgo
    Dec 9, 2014 at 9:01
  • Possible duplicate of Prevent auto-loading of tabs in Firefox when starting browser Jan 19, 2016 at 16:58
  • No it is not. The other question is just slightly related. As I stated above, this works fine when starting firefox. But I am searching for something that works also while operating normally.
    – masgo
    Jan 20, 2016 at 8:58

3 Answers 3


This works for me on Firefox 45: the Load Tab on Select add-on prevents background tabs from loading until selected. According to the description, this addon is only useful if you have browser.tabs.loadInBackground set to true.

As a suggestion, you might also want to use the Suspend Tab add-on, which automatically suspends background tabs to save the memory. The functionality is configurable and you can choose the delay before suspending tabs.


This option is also provided by the Auto Unload Tab add-on, which is in my opinion one of the richest add-on for dealing with tab unloading.

Among other features, it allows you to configure how to deal with (newly opened) background tabs:

  • Keep them loading (default approach);
  • Never load them until visited;
  • Load whitelisted sites immediately, others only on open;
  • Load background tabs one-by-one, which avoids slowing down Firefox when trying to load multiple sites at once;
  • Load background tabs and then unload them, "for better add-ons compatibility" (whichever this means).
  • No longer exists?
    – endolith
    Jun 13 at 1:43

The Extension Load Background Tabs Lazily does this quite well. Tabs are still loaded in the background, but only one at a time. This no longer makes Firefox and the whole PC slow when you open a lot of tabs at once. It also has an option "Limit the amount of tabs loaded by this extension" which, if set very low, will prevent most background tabs from loading.

  • I didn't find a way to adjust this extension to prevent all background tabs from loading (which is what this question asks for). And it doesn't work for me at all. Multiple mouse middle-clicks open multiple background tabs which ALL load.
    – summerrain
    Jul 9 at 18:27
  • It does not prevent ALL tabs from loading. The reason I asked this question is that I have bookmark folders that I like to open by middle click on the folder. This will open all bookmarks. e.g. I have a "news" folder which 15 bookmarks. Middle click on it renders my browser unusable for several seconds because of all the background loading. With this extension only ONE tab loads at a time, this is quite a low load. You can also set "Limit the amount of tabs loaded by this extension to" 2 then loading stops completely after two tabs have been loaded. This works great for me
    – masgo
    Jul 10 at 19:39

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