4GB is plenty of RAM for a web browser with many tabs, especially with an SSD for backing virtual memory. If it isn't there is a memory leak, and if there is a leak, 8GB is as bad as 12GB.
My MBA has 4GB and I constantly forget, because it is enough, and I am constantly surprised that it doesn't have 8GB.
All modern web browsers save and restore sessions across restarts.
> 4GB is plenty of RAM for a web browser with many tabs,
I always up-to-date Firefox, so hopefully the memory leaks are minimal. I reboot my Linux machine every month-ish and don't exit Firefox unless necessary. I always keep a few "app" tabs pinned, only a couple of them are heavy. I have 4GB of RAM and turned swap off for an experiment. Sure enough, after a couple weeks of browsing and keeping about 25 tabs open, Firefox's memory consumption would creep up and up and eventually it would crash.
I can only guess/hope that there are memory leaks involved.
My MBA has 4GB and I constantly forget, because it is enough, and I am constantly surprised that it doesn't have 8GB.
All modern web browsers save and restore sessions across restarts.