Do you remember this change Mozilla added to Firefox version 8 : Firefox doesn’t load all tabs from the previous session on startup by default it loads them when you visit them, on that, a bug created 8 years back to automatically unload or discard tabs when the memory is running out, the news is the bug has been fixed today and performance improvement has been landed in Nightly and enabled by default.
The complaint we heard from some users since Multi-process architecture (e10s) launch is, Firefox is consuming more memory, your system specs, extensions installed, needs to take into account for this. You should know, e10s also bringing stability, responsiveness and performance improvements, if you’ve system configuration with less RAM, set the number of content processes down to a number which you feel comfortable and disable hardware acceleration.
Note: The above screenshot is for representaion only. It has been taken from a old article.
But the default action taken by Firefox also helps in a situation where you’re doing multitasking like listening to music from one tab and working in another and you’ve more number tabs open.
Firefox 67 to unload tabs when memory is low
What this means is Firefox jumps in and discards the tabs in the following order when it detects some memory is needed, the browser then unloads
- first tabs that are not playing audio and not pinned
- Pinned tabs not playing audio
- tabs playing audio
Do note, priority will be given to regular tabs first over pinned tabs.
When Firefox detects there is not enough memory to or tabs open are using more resources, it tries to discard some tabs to free the memory.
The change can be controlled by changing the preference value
browser. which is set to true in Nightly edition by default for now on Windows.