I found some information about the number of tabs that concurrently restore on a session restore, but it has long since been further developed in the product. I don't think the same method you seek will solve your problem, which I think is limiting the number of loaded tabs that are open to optimize your available bandwidth.

Sandboxing, aka e10s is a feature that has been developing this year and has landed a few versions ago into release. It gives each tab its own process (on the OS level). As far as on the network and concurrent requests when multiple tabs are open,

This is why the addon no longer works: https://developer.mozilla.org/en-US/docs/Archive/Add-ons/Legacy_Firefox_for_Android/API/BrowserApp/tabs It looks like the tab api is not one that is accessible to add-ons, post 57.

There is the tab limiter addon as well. That might be a new method.

I did a bit more research on how multicasting works - you can limit the number of automatic connections made in Firefox:

• https://support.mozilla.org/en-US/kb/how-stop-firefox-making-automatic-connections

@guigs Thank you for this thoughtful reply.

First I am aware how Firefox has recently done away with the legacy API in place of the new web compiler. I did not know the new security functions would limit any addons control over the webbrowsers tab controls.

I am currently looking into your provided link on limiting the number of automatic connections, this will be helpful for managing my limited bandwidth.

Still, I do hope in the future my original suggestion could be implemented as an actual Firefox naitive feature as it is a very good way to manage resources of any user who chooses to open a bulk of new tab links at any given time.

Thanks again.

Not a problem, I was going to file a bug/feature but came across a couple of bugs - This one has tabs load progressively on a session restore: https://bugzilla.mozilla.org/show_bug.cgi?id=1139608

If you don't mind me asking, for this use case, what is the bandwidth we are limited to? I would file it here: https://bugzilla.mozilla.org/enter_bug.cgi?product=Composer&component=Tabs

@guigs To answer your quetsion; I'm limited to about 3mbps/0.6mbps down/up speed via Sonic.net DSL internet.

I hope that answeres your question. I will contribute to your report if you choose to file a bug report.

Thank you again, and apologise for the late response.

guigs said

Not a problem, I was going to file a bug/feature but came across a couple of bugs - This one has tabs load progressively on a session restore: https://bugzilla.mozilla.org/show_bug.cgi?id=1139608 If you don't mind me asking, for this use case, what is the bandwidth we are limited to? I would file it here: https://bugzilla.mozilla.org/enter_bug.cgi?product=Composer&component=Tabs

Hello, can I know what should be the new firefox behavior when we launch it with many tabs opened ?

My firefox quantum loads all tabs, and there is no more an option to avoid loading tabs until we visit them.

I also cannot find a plugin to achieve this. Any help ? Thanks a lot.

You can consider to lower the value of some network prefs on the about:config page that set the maximum number of connections.

• network.http.max*connections

Sorry but why ?

I only want that Firefox does what it was formerly perfectly doing: DO NOT LOAD TABS UNTIL I VISIT THEM

Any more help ?

Thanks a lot.

For tabs loaded when you start Firefox you can set browser.sessionstore.*demand prefs to true on the about:config page to prevent them loading.

• browser.sessionstore.restore_on_demand
• browser.sessionstore.restore_pinned_tabs_on_demand