Warning: Editing about:config can introduce stability issues or security risks. Proceed with caution.
Step-by-step guide:
Conversion formula: MB × 1024 = KB. For 250 MB, enter 256000. Browser.cache.memory.capacity
True for most. Unless you have a specific bottleneck or benchmark data, -1 is the safest, most intelligent setting.
Replace the static numeric pref with a Smart Memory Cache Controller in browser settings (under Performance or Privacy & Security). To edit:
Do not rely on synthetic benchmarks. Run a real test:
| Value | Meaning |
|-------|---------|
| -1 | Default (recommended). Firefox automatically manages the cache. |
| 0 | Disabled. No memory caching. Drastically slows down session navigation. |
| 65536 (64 MB) | Conservative fixed limit. |
| 131072 (128 MB) | Moderate fixed limit. |
| 262144 (256 MB) | High fixed limit (rarely needed). | Conversion formula: MB × 1024 = KB
To revert to automatic management, simply set the value back to -1. If you created the preference, you can right-click it and select Reset.
There are three distinct profiles of users who might want to deviate from the -1 default.