Caching
Caching is the core mechanism that makes Fast.site fast. It stores copies of your website's responses at our global Edge Servers to serve content instantly.
How caching works
Cache MISS (First Request)
Fast.site forwards the request to your origin server, returns the response, and stores a copy in memory.
Cache HIT (Subsequent Requests)
The cached copy is found and served in under 5ms without contacting your origin server.
Expiration
Entries expire based on your origin's Cache-Control headers or rules you define.
Cache Rules
Override what gets cached and for how long — without modifying your origin server or deploying code.
| Rule Name | Condition | Action |
|---|---|---|
| Cache static assets | URL starts with /static/ | Cache TTL = 30 days |
| Never cache API | URL starts with /api/ | Bypass Cache |
| Cache images | Extension is .jpg, .webp | Cache TTL = 1 day |
Response Headers
fr-CacheValues: HIT, MISS, BYPASS. Indicates if content came from cache or origin.
fr-Cache-AgeNumber of seconds the cached object has been stored at the Edge.
Cache Purging
When your website content changes, manually clear cached copies to force a fresh fetch from your origin.