HTTP Cache-Control Header & CDN TTL Calculator
Calculate exact seconds for max-age, s-maxage, stale-while-revalidate, and stale-if-error directives across browsers and CDNs (Cloudflare, Fastly, CloudFront) with cache lifecycle modeling.
Caching Policy & Target Directives
RFC 9111 Cache-Control Header
MAX CACHING (1 YEAR)
Cache-Control: public, max-age=31536000, immutable
Browser stores asset for 365 days; never revalidates due to immutable flag
Web Server Configuration Snippets
Nginx (nginx.conf):
add_header Cache-Control "public, max-age=31536000, immutable";
Cloudflare Pages / Netlify (_headers):
/* Cache-Control: public, max-age=31536000, immutable
Cache Lifecycle Breakdown
Browser Fresh Phase:
365 Days (31,536,000s)
CDN Edge Fresh Phase:
Matches browser max-age
Stale-While-Revalidate Window:
Disabled (0s)
Origin Offload Efficiency:
> 99.9% (Near-Zero Origin Load)