Browser.cache.memory.capacity |work| Jun 2026

This setting is found in the ( about:config ). Step-by-Step Instructions

limit the memory cache to a reasonable value - Mozilla Bugzilla Browser.cache.memory.capacity

You have 32GB or 64GB of RAM. You typically keep Firefox open for days with 50+ tabs. You frequently revisit complex web applications (Slack, Figma, Gmail). This setting is found in the ( about:config )

On Linux distributions with limited RAM, you might want to completely bypass memory caching to free RAM for the kernel's filesystem cache. Set to 0 or 8192 (8 MB). Browser.cache.memory.capacity

Historically, the MozillaZine community suggested these starting points for older hardware: Physical RAM Suggested Cache Value (KB) -1 (Automatic) Related Settings for Better Performance

Adjusting this setting can have significant effects on browser performance: