Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Want to open previous session without ever reloading tabs

I've thought about this question for years, and finally decided to post a complete and clear explanation, as I think this undocumented feature would provide an amazing speedup to Firefox if it were either documented or added to the product.

FIrefox currently provides two options during startup: to reload all tabs in all tab groups, or to reload only the current tab (and deferring the reload of all the other tabs until the first time each is chosen for viewing).

In both cases "reload" means a complete or partial read (I'm not sure which) from the webserver of each tab, ignoring the cache.

But, almost always, the complete page content and detailed state of all tabs in all tab groups are already contained in the profile and the cache (right?), so the entire reload process, which can take several seconds up to a minute FOR EACH TAB, is actually unnecessary.

My question is whether there is an about:config option to reload all tabs in all groups from the profile and the cache, which are both stored in local files, in order to restore their previous content, instead of reading anything from the Internet at all.

This would make Firefox start MUCH more quickly, and so would provide benefit to untold thousands of people.

If there is no such about:config option, can the developers be asked to add this feature to the Tools>Options>Tabs dialog box, please?

Not only I, but everyone who leaves tabs open for days or weeks at a time, across system shutdowns, will thank you.

David Spector Springtime Software

I've thought about this question for years, and finally decided to post a complete and clear explanation, as I think this undocumented feature would provide an amazing speedup to Firefox if it were either documented or added to the product. FIrefox currently provides two options during startup: to reload all tabs in all tab groups, or to reload only the current tab (and deferring the reload of all the other tabs until the first time each is chosen for viewing). In both cases "reload" means a complete or partial read (I'm not sure which) from the webserver of each tab, ignoring the cache. But, almost always, the complete page content and detailed state of all tabs in all tab groups are already contained in the profile and the cache (right?), so the entire reload process, which can take several seconds up to a minute FOR EACH TAB, is actually unnecessary. My question is whether there is an about:config option to reload all tabs in all groups from the profile and the cache, which are both stored in local files, in order to restore their previous content, instead of reading anything from the Internet at all. This would make Firefox start MUCH more quickly, and so would provide benefit to untold thousands of people. If there is no such about:config option, can the developers be asked to add this feature to the Tools>Options>Tabs dialog box, please? Not only I, but everyone who leaves tabs open for days or weeks at a time, across system shutdowns, will thank you. David Spector Springtime Software

Modified by David Spector

All Replies (3)

Hello David,

Thank you for the idea! The developers don't check this forum very often, so it would be great if you could file a bug on Bugzilla to add this in :)

Note: When filing a bug, please follow our Bug Writing Guidelines. Thanks!

If servers have allowed the pages to be cached, and the cached pages have not expired, I suspect that what Firefox does is check with the server for updates rather than completely disregard what has been cached. I haven't tested this myself.

If you were to start up in "Work Offline" mode, I suspect Firefox would do what you want, but I don't know how to trigger that mode at startup. Perhaps not being connected to any network would do it?

Thank you. I have created this bug report.