6

When I use Firefox I often have many tabs and many windows open (even more so now that they have panorama). I often use the session restore feature because I don't want to lose all my open windows when installing a new add-on or restarting my computer for updates.

However, with so many tabs open it takes a really, really long time for Firefox to load all the tabs.

I'm looking for an extension that will open a placeholder tab for all of the websites on session restore but won't actually load the page until I click on that tab to bring it to focus.

Basically, it would look like I had 40 tabs open, but until I click on that tab, it won't be taking up any more memory than an about:blank page.

Improve this question
6
  • Possible duplicate of Prevent auto-loading of tabs in Firefox when starting browser
    – r_alex_hall
    Commented Jan 19, 2016 at 16:58
  • @CroadLangshan: Is browser.sessionstore.restore_on_demand set to true?
    – harrymc
    Commented Mar 30 at 9:10
  • @harrymc yes browser.sessionstore.restore_on_demand is set to true
    – Croad Langshan
    Commented Mar 30 at 10:33
  • @CroadLangshan: Try the add-on Load Background Tabs Lazily.
    – harrymc
    Commented Mar 30 at 10:54
  • That says Allow only a specific number of new background tabs to load at one time. It sounds like it serializes tab loading (N tabs at a time are loaded, progressing until all tabs are loaded without user interaction). I, and the original questioner I think, am rather looking for something that prevents tab loading until the tab is selected (e.g. by clicking on the tab, or by keyboard navigation).
    – Croad Langshan
    Commented Mar 30 at 11:03

3 Answers 3

Reset to default
4

You could use BarTab, but I find it doesn't work too well with Firefox 4/5.

Another more reliable way is to use the new about:config property, browser.sessionstore.max_concurrent_tabs.

Go to about:config in firefox and search for browser.sessionstore.max_concurrent_tabs. Set the integer value to 0.

Now when you start up Firefox, only the first open tab will be opened. All the rest need to be clicked/focused on before they are actually loaded.

enter image description here

Improve this answer
1
  • and also now with the Tab groups feature, FF only loads active tab group.
    – Reddy
    Commented Sep 5, 2011 at 12:11
1
+50

As of March 2024, Firefox Version 124, that is default behavior for Firefox (it has been there for many many years, see the Edit). After a restart, Tabs will only be loaded once you actually click on them. This works on Windows, and it should work the same way on Mac or Linux (although I cannot test this).

So, go to about:support and click on "Refresh Firefox". that should eliminate any user setting which could interfere with such behavior.

If that should not help, try uninstalling and reinstalling.

EDIT:

In this thread from 2020 a user asks to disable the feature, and in this other thread from 2017 a related question is asked: which means that the functionality has been there for many years. More interestingly, in about:config there are two distinct flags:

  • browser.sessionstore.restore_on_demand when set to false (default is true), will load all tabs on startup.
  • browser.sessionstore.restore_pinned_tabs_on_demand will do the same only for pinned tabs.

So, by using pinned tabs you can have some of your tabs auto-load, while the others will not load on startup.

Improve this answer
4
  • This is correct. The traffic I was seeing on firefox startup, which seemed implausibly extensive to be from anything other than tabs, was coming from the various sources here support.mozilla.org/en-US/kb/… plus "web push", which is not listed there. To verify this (Arch Linux Firefox 124.0.1) I had to turn all that off, then set dom.push.enabled false to disable web push (I may have had to turn off more in addition). With all that turned off, I see only DNS traffic from firefox on startup with "Open previous windows and tabs" enabled.
    – Croad Langshan
    Commented Mar 31 at 11:35
  • Just to add: I'm not suggesting to people to turn all those off: I did that to verify the tab behaviour. But now I mention that, it's also true there's also a lot in there that as from my user perspective provides no benefit to me, other preferences split oddly between user-visible and non-user-visible settings in ways surprising to me, and yes much that should concern anybody who worries about concentration of power and surveillance!
    – Croad Langshan
    Commented Mar 31 at 11:41
  • Do you have a citation for that? If so I think it would be great to add it
    – Croad Langshan
    Commented Mar 31 at 11:42
  • @CroadLangshan see my Edit of the answer
    – 1NN
    Commented Apr 1 at 19:04
0

BarTab will do this.

BarTab can intercept when tabs are loaded in the background or restored after a browser restart and will only load the content when the tab is actually visited. It also allows you to free memory by unloading already loaded tabs, either manually or automatically.

Improve this answer
0

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .