Thomas Abeel

After a while every Firefox user notices that FF uses copious amounts of memory. Below are some tricks to remedy the large amounts of memory Firefox consumes.

While these tricks reduce the amount of memory that Firefox hogs, in general revisiting pages will be slower because Firefox caches less data.

Type 'about:config' in the address bar of Firefox and change the following keys.

browser.sessionhistory.max_total_viewers

Pages that were recently visited are stored in memory in such a way that they don't have to be re-parsed. This improves performance when pressing Back and Forward.

Set this to a low-value (0 or 1).

browser.sessionhistory.max_entries
Firefox saves 50 recently visited website in memory in order to facilitate quick browsing.

Set this to a lower value (5 or even lower).

config.trim_on_minimise
You can also instruct Firefox to release the memory when minimized. Right click on any space in the list of configuration settings and select the context command ‘New| Boolean’. Enter ‘config.trim_on_minimise’ and ok. Click on ‘true’ in the following dialogue and again confirm with OK. You have to restart Firefox for this one to take effect.

browser.cache.memory.capacity
When images are loaded, they can be cached so they don't need to be decoded or uncompressed to be redisplayed. This preference controls the maximum amount of memory to use for caching decoded images and chrome (application user interface elements).

This value is in Kb, and cannot be lower than 256. The lower you set this, the less memory Firefox can use to cache images. (browser.cache.memory.enable must be true for this preference to take effect)