1 yr. ago • 97%

TIL that on Firefox you can unload tabs from memory without closing them

The feature is called Tab Unloading, and weirdly enough they made it not easy to access despite its usefulness.

You basically have to type about:unloads in the address bar and hit enter. If you then click on "Unload", it will put the least used tabs to sleep. If you keep clicking that button until it's greyed out, you'll have unloaded all your tabs from memory.

This feature is handy if you want to temporarily switch to something that is memory hungry without having to close your 100 tabs.

51 comments

Your Firefox should be doing this automatically when it detects the system needs more memory. You shouldn't need to do it manually in almost any case

109
- Your OS should do this automatically, your programs shouldn't worry about cold memory.
  
  19
  
  Your OS can't decide when a tab is inactive though, given that they can run code, play media, etc. at arbitrary times.
  
  58
  
  Swapping anonymous pages is an extremely poor "solution" to cold memory. It's the big hammer approach that technically always works but isn't optimal for ...anything really. That's the best the kernel can easily and quickly know however which is why it's done at all.
  
  It'd be much better if the process could shave off memory usage using its own domain knowledge. In the example of firefox, it's much faster and less jarring to the user to have 10 tabs reloaded from the web (browser shows a spinner as usual, doesn't lag) rather than swapped back in from disk (entire browser lags and it probably even takes longer).
  
  There's no reliable mechanism to signal any of this to me knowledge however, so processes must guess the right time to do discard memory pre-emtively.
  
  5
  
  Edge does this very aggressively and I hate it… Also I believe that Chromium based browsers use more memory per tab, so that might be the reason why it feels more aggressive. Firefox does this very rarely.
  
  2
- Nope! Not happening or at least not soon enough. Neither on macOS or Linux (can't speak for the stupid platform).
  
  Firefox will happily keep tabs open, even if macOS reports major memory pressure or Linux needs to invoke the OOM killer because it's Gigabytes into swap.
  Not to speak of what happens before memory pressure is reached; Firefox will also happily use all of your memory even if you'd rather have it free for something else you're going to do next.
  
  4
Firefox does this automatically to prevent crashing. There's no real reason to unload tabs manually. If your operating system or Firefox needs more memory, then it will unload the tabs automatically. Unused ram is wasted ram. Don't be scared by ram usage going up, it gets freed on demand.

64
- Permanently Deleted
  
  9
  
  No, only into your display name.
  
  9
- There are reasons, and there are addons that allow you to unload tabs via their right click menu.
  
  For me it is a way to keep tabs in a window for organization without them using cpu. In some sense it's like replacing tabs with bookmarks that integrate into the browser like tabs.
  
  3
Just close unused tabs smh

Can't understand people who're juggling 100s of tabs

18
- That's fine, do what works for you. I usually have 50+ tabs open, sometimes >100. I'm a software dev, so I'll typically have the following:
  
  a dozen or so JIRA tickets
  
  a dozen or so GitHub PR tabs
  
  a dozen or so documentation tabs
  
  several background tabs with stuff in listening to (usually music or streams)
  
  several SM or news pages (for breaks)
  
  When I finish a project, I'll close everything and start it all over again. I basically use tabs as a mixture of to-dos and bookmarks, but only for things I need in the short term.
  
  My personal computer usually only has 20 tabs or so, mostly with gaming wikis or shopping pages.
  
  It works well for me.
  
  9
- Especially for school, I would have 10 to 15 tabs open per research rabbit hole. With lots of different assignments due, I'd have maybe 3 or 4 of these going at a time. It's much easier to keep them open than to bookmark them and try to find them later.
  
  8
- Personally I use simple tab group that allow you to separate tabs into groups that you can open in different windows. It's extremely useful but it means sometimes if you switch between multiple tab groups you might have a lot of tabs open, but using this would allow you to majorly mitigate that problem.
  
  6
- I just say eh this one is important but I can't rn so I'll deal with it later. Anyway, 60 tabs waiting for me on FF Android. Idk how much I tabs are stashed on PC lol. ADHD struggles are real
  
  6
- (i had over 2000 earlier)
  
  4
- Or use oneTab.
  
  1
- This, if you want to act on something later, just create a bookmark and set a reminder, act on what you need, then close and move on, don't clutter your browser and your head.
  
  Usually, i open one window for each task, so i don't get a lot of unrelated content mixed up and loose focus. I rarely need more than 1~5 tabs.
  
  -4
- They cannot juggle 100 tabs.
  
  Simple as that
  
  Its not possible to manage for anyone.
  
  Theyre just too dumb to close them
  
  -4
  
  Never have I been so offended by something I 100% agree with
  
  2
I use this extension: https://addons.mozilla.org/en-US/firefox/addon/discard/ which provides an option in the context menu for tabs to discard them. I don't use it often but it can be helpful if your browser is slowing down.

12
I would like the opposite though. When I used chrome, my WhatsApp web tab would load even if I didn't open it, so I still got notifications. In Firefox I have to manually switch to that tab every time I open it.

10
- I find pinning my WhatsApp tab sorts that out, it seems to autoload pinned tabs into memory on launch.
  
  19
  
  If this works, THANK YOU. It's been annoying me for so long.
  
  EDIT: it does work.
  
  5
"Auto tab discard" is the name of the add-on I use that also uses this functionality. Highly configurable for automatic discarding (based on total count for example), and also allows manually discarding with a click (or shortcut, I think).

10
addon Tab Suspender does this automatically

10
- This one?
  
  1
- Bump
  
  0
I use the addon Sideberry (for vertical tabs) and it brings the option to unload specific tabs with it's context menu.

I don't get why about:unloads doesn't let the user decide which specific tabs they want to close.

9
use auto tab discard.

8
Hey thanks for sharing

6
Where does it get unloaded to?

5
- From what I understand it basically just saves the minimal state possible (URL, form inputs), which is lighter than keeping all the rendering details in memory, so maybe that minimal representation still stays in RAM as its footprint would be negligible.
  
  8
  
  It doesn’t save form inputs because when you click a suspended/unloaded tab, it reloads the whole page. Everything unsaved on that page is lost.
  
  I really hope some day Firefox will work the way you say, though.
  
  2
- It gets thrown away. When you go back to the tab it will effectively reload.
  
  (It will attempt to save some extra information such as scroll position and form inputs but this isn't 100% reliable so I would treat it as a nice-to-have not something to rely on.)
  
  5
- /dev/null
  
  5
But how else am I going to use up all 64GBs of ram?

5
Huge missed opportunity to name it Diet Tab...

4
IceRaven, Android FF fork, has this feature as an option, and it's very cool when using permanent private browsing mode. It makes it less likely that the OS will kill the browser in the background.

2
I'm pretty sure that Chrome does this automatically. When I work I usually need about 98,000 tabs open at a time and often I don't actually click any of them but I need them.

Anyway I will often open a tab and have to wait to it for it to load. But I've played around with it and I don't seem to be able to get consistent results so I'm not sure what parameters it's using.

2
- What the hell are you working?
  
  7
  
  Research :clueless:
  
  5
  
  Right now?
  
  Internal ticket tracker
  
  Internal knowledge base system
  
  OneNote with the actual knowledge base system because the knowledge base is never updated
  
  Corporate emails
  
  Client emails
  
  Spam messages blocking system
  
  Shift timetables
  
  Engineer to English random acronym guide. Unless you know what ROD means.
  
  O365 files
  
  O365 online Word document
  
  Software phone app
  
  YouTube
  
  PC parts picker website
  
  Steam website
  
  UPS live chat
  
  Lemme
  
  So a fair few. Although I can probably close the UPS live chat tab because I'm getting nowhere with these idiots.
  
  3
- Firefox also does this automatically, and you're not supposed to mess with it.
  
  3
- No, no you don't. IF you aren't accessing stuff on them, you don't need them open. Keeping 100 tabs open for later, is stupid.
  
  -5
  
  It also doesn't affect performance because Chrome closes them as needed so why not?
  
  2

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