Firefox 4 about:memory

You blame Firefox 4 to be a memory hog? Check it out first by typing about:memory in the address bar. You'll get a nice detailed report of your browsers memory usage. While it's not guaranteed you'll understand every statistic available in the report, you can at least peek at the overall memory use, and see how much it's fragmented by comparing "memory mapped" and "memory in use" numbers.

I definitely see memory usage of my browser only go up during regular use, but it's not really problematic, considering there are gobs of RAM in today's computers. And there has also been a steady improvement in memory usage efficiency, 3.0 has been the biggest hog for me, 3.5 was quite an improvement, and now 4.0 is absolutely the best of them all. Alive and kicking (though, much of the responsiveness improvement comes from better javascript engine, I suspect). It's good to know that Mozilla plans even more improvements on that front with Firefox 5, 6, 7... which they advertise will be released this year!



571MB memory in use, is that much?

No, but it gets tenfold over time. Mine is using 1240MB right now.

I found this plugin

and it really reduced my memory use from 1 GB to somewhere between 100 MB to 200 MB. You should not forget to turn the plugin on!

Depends on how much total memory you have, nowadays it's pretty normal to have 4/8GB of ram.

Another also very useful tool for checking out general memory usage of apps in Linux is KSysguard system monitor. If you right click on a process in process list you have an option to view detailed memory info.

And you just gave me an idea to compare firefox's memory accounting with the output of standard linux ps utility. And they don't match at all. ps reports 882MB virtual size, and 222MB resident set size, while firefox says 551MB mapped and only 241MB in use. Strange...


I think author has assume that everyone in this earth has lot of memory in their boxes ,which is not correct.

Second..firefox is seriously prone to memory hogging over the years and mozilla overlooked it for all the time doing some unnecessary work here and there.I have been using firefox for ages and on different GNU/Linux distros. And as I progess and keep adding features my mozilla folks and adding plug-in by me. Its getting slower and slower .

Third I have seen in Slashdot that first time Mozilla guys noticed that firefox is memory hogging application ,that they are developing over the years.Thank god some common sense prevail at last.

Hope this time mozilla folks make it right.Something like make a specific build for GNU/Linux,which runs faster with native library.


"I definitely see memory usage of my browser only go up during regular use, but it's not really problematic, considering there are gobs of RAM in today's computers."

I hate, HATE this argument. Having heaps of RAM is not a prerogative for it to be wasted; I'd hate not being able to run a virtual machine - or any other application - because some memory-gobbler application is filling up all my RAM, and Firefox sure does that.

Also, about:memory doesn't work on Fedora 15.