[StavrosK]

I don't know which Firefox you're using, but I want it. Mine is super laggy all the time, even with one or two tabs open. Opening a new tab takes half a second, visiting a new page takes half a second, going back takes half a second. It's extremely frustrating to use, and I don't even have that many extensions or history pages.

[nachtigall]

You might want to "Refresh" your Firefox: https://support.mozilla.org/en-US/kb/refresh-firefox-reset-a... It help for me. Especially if you many add-ons over time that might have done all kind of things to your settings...

Backup/Restore your bookmarks etc. afterwards as it cleans up everything. Resetting everything afterwards took 1h for me but was totally worth it in retrospective.

[semicolon_storm]

6 tabs, 1GB of RAM, ~20% CPU usage for me on Firefox. I have a few basic QoL plugins like LastPass, uBlock, and NoScript. It's absolutely ridiculous. I want to keep using FireFox, but it's forcing me to consider moving to another browser.

[mixmastamyk]

Vacuuming your profile might help:

    #!/bin/bash
    killall firefox
    for file in ~/.mozilla/firefox/*.default/*.sqlite; do
        echo sqlite3 "$file" VACUUM
        sqlite3 "$file" VACUUM
    done

I do it in my once-a-month cleanup script.

[majewsky]

Looking at `find ~/.mozilla/firefox -name \.sqlite`, there are some more such databases for window.localStorage and the like. So this could be generalized to

  find ~/.mozilla/firefox -name \*.sqlite -print -exec sqlite3 {} VACUUM \;

[Twirrim]

For those on OS X, it looks like:

find $HOME/Library/Application Support/Firefox -name \*.sqlite -print -exec sqlite3 {} VACUUM \;

[na85]

I remember the days when leaving Windows meant not having to futz with cleanup scripts.

What happened?

[sp332]

Firefox and SQLite have actually improved a lot since those days. And it's not like Firefox uses a different database system on different platforms, it's all exactly the same.

[mgurlitz]

When was this? I recall having to use Cocktail with OS X (10.2-10.9) because the system maintenance scripts would never run if my laptop was off/asleep at midnight. In general, Unix users have had to use cron scripts almost since its origin.

[SAI_Peregrinus]

254 Tabs, 3.3GB of RAM, ~2% CPU usage for me on Firefox 50.1.0. You've got something wrong (and I have too many tabs open)...

[mkj]

If there are only 6 tabs it should be easy to narrow down which is a problem?

[richardboegli]

Try Pale Moon.

Forked from Firefox 27 and super fast.

http://palemoon.org

[nomight]

Incorrect.

Pale Moon 27 is based on Firefox 38 for back-end and Firefox 24 (ish, with some 26-isms) for the front-end. That said, I'd still recommend it. :-)

[sp332]

Opening a tab is the fastest thing about Firefox. I mean it plays a little animation, but you can ignore that and start typing immediately after ctrl-t.

[mrob]

You can disable the animation by setting browser.tabs.animate to false in about:config.

[StavrosK]

Ooh, snappy, thanks for the tip!

[aidenn0]

That's bizarre; I just held down C-t for a few seconds and tab were opening at the rate of maybe 5-10 per second and it is now using 630M of ram with 98 tabs open. A-1 to switch back to the tab I had open was instantaneous (though the tab bar was animated and took almost 2s for the scroll animation to finish)

I'm not sure how the GP has over 200 tabs open with less RAM used than 98 empty tabs though.

[eveningcoffee]

Based on my personal experience I think you are living in some parallel universe. Perhaps you post some other parameters about your system?

[StavrosK]

It's a 2013 MacBook Air, and my desktop is some custom thing with an i5, 16 GB RAM and a Samsung Evo SSD. They're both equally laggy, to the point that my browser froze for half a second while posting the previous comment (and regularly does so). However, after running the cleanup script in the sibling comment, it at least appears to not freeze.