How can I unload a tab manually?

Firefox has a setting "Don't load tabs until selected" (see How do I make Firefox 13 Load All My Tabs on Startup or when Resuming Reload). I like that behaviour.

I am searching for a way to "deload"/deactivate a tab manually for a session (until I reload it).

It should stop all running JavaScript functions and plugins (like Flash). The whole webpage content may disappear until I reload/re-activate the tab, but that is not a requirement. The title has to be displayed as tab label (like it is the case with the startup setting, too).

The workaround would be to restart Firefox and don't switch to the tab I want to be deactivated. This is pretty annoying, of course.

EDIT: Here is what I found so far

BarTab
- no longer being maintained (see why)
BarTab Lite
- (thanks, @bytebuster)
- seems to miss this functionality from BarTab
Dormancy
- experimental; comes with warning that it "may eat your session"
Suspend background tabs
- (thanks, @Greck)
- experimental; is not exactly what I'm looking for, but could be an alternative (doesn't disable videso/Flash, though)
Tab Mix Plus
- Feature request: Unload Tab feature
Tab Utilites
- (thanks, @bytebuster)
- seems to offer this functionality only for automatic unloading
- Feature request: Add "unload tab" to tab context menu.
UnloadTab
- removed from addons.mozilla.org (who knows why)

unor

Posted 2012-08-13T13:48:23.253

Reputation: 2 749

2UnloadTab appears to be back. – BrenBarn – 2014-06-29T01:29:07.387

Follow-up: Firefox add-on that suspends inactive tabs, to use less memory

– kenorb – 2018-02-28T12:01:22.557

@billc.cn yes that's that point. An intermediary step between bookmarks and current use. I use bookmarks for my long term memory and have no bookmark bar. – sinekonata – 2019-03-04T16:26:03.347

You can pin it as an app tab as a work around, but you do realize you're effectively moving the bookmarks bar above the address bar right? – billc.cn – 2012-08-13T23:00:32.363

Answers

In one of the links you referenced at Tab Utilities: Feature Request, there is already an answer from the developer (scroll down to comment no. 4) on how to do this. The answer is to:

Add the Restart Tab item to the context menu.

Why it's called "Restart Tab" and not "Unload Tab", I don't understand, but he says you can just change it if you want. Set:

extensions.tabutils.menu.context_restartTab.label to "Unload Tab".

By the way, at the moment it only works on tabs that are not selected/focussed. In other words, if you do "Restart Tab" on the currently open tab, it will just reload. You have to switch to another tab, then right-click on the tab you want to unload, and choose "Restart Tab".

Here are the instructions from the developer, I updated them a little:

Set browser.sessionstore.max_concurrent_tabs to 0 in about:config. (BarTab Lite or Load Tabs Progressively extension should also work.) [ the above is outdated, in current versions of Firefox, go to preferences/options for Tabs, and check "Don't load tabs until selected". ]
Unload tabs manually with Restart Tab or Restart All Tabs menuitem. [ first you have to make sure the "Restart Tab" item is added to the context menu, in Tab Utilities preferences/options -> Appearance -> Menus -> Tab Context Menu ]
Unload tabs automatically after a specified period of inactivity with extensions.tabutils.restartAfter option (minutes).
Tag bookmarks with "norestart" to make an auto-unload black list.

Sum Guy

Posted 2012-08-13T13:48:23.253

Reputation: 116

A workaround is: by forcing the reloading of a tab using CTRL+F5 and stopping it so far (using the cross in URL bar) it may left you (with luck) with a blank page (or almost blank).

s.k

Posted 2012-08-13T13:48:23.253

Reputation: 131

A great temporary 'do not disturb' for Discord :D – starbeamrainbowlabs – 2018-10-29T20:40:31.120

1You can use the ESC key to stop a tab from loading, if you want a full keyboard variant. – leokhorn – 2019-01-30T10:02:04.790

All Tabs Helper and Auto Unload Tab do this, among other things.

Nelson Cevallos

Posted 2012-08-13T13:48:23.253

Reputation: 31

Auto Unload Tab works well for me and is being maintained it appears. Thanks! – dbasch – 2016-04-04T08:13:33.437

As of December 2018 the Auto Tab Discard addon appears to be a great option.

The source code is available at https://github.com/rNeomy/auto-tab-discard.

Marc.2377

Posted 2012-08-13T13:48:23.253

Reputation: 1 072

https://addons.mozilla.org/en-US/firefox/addon/unload-tabs/

New (Sept 2019) solution that seems to get around the issues that killed earlier addons that provided this feature.

Ambiwlans

Posted 2012-08-13T13:48:23.253

Reputation: 383

There is the extension BarTab Lite X. This is a light extension. Its feature for unloading tab works with recent Firefoxes.

However, better check that unloaded tabs don't mess up Firefox' session restore.

Nicolas Barbulesco

Posted 2012-08-13T13:48:23.253

Reputation: 371

If you have e10s enabled, taskkill /f /im plugin-container.exe or your OS equivalent is a pretty easy solution.

Firefox will think the content process has crashed, but that is wrong.

Clicking on a tab will reload it.

Charles Milette

Posted 2012-08-13T13:48:23.253

Reputation: 93

I was searching for a why to freeze the current state of a tab, so maybe these two addons might be helpful for you too:

Freeze, Tab Suspender

Discard tab

"Unloading" was announced by a users comment, and searching that let to these results:

Unload tab (experimental, exactly what you wish, set on a state like on startup)

Unload tabs (all, or all but current)

PythoNic

Posted 2012-08-13T13:48:23.253

Reputation: 157