Proper caching headers dramatically improve performance. This guide covers HTTP caching mechanisms.
Cache-Control Directives
Common Directives
Cache-Control: public # Cacheable by anyone
Cache-Control: private # Only browser can cache
Cache-Control: no-cache # Must revalidate
Cache-Control: no-store # Never cache
Cache-Control: max-age=3600 # Cache for 1 hour
Cache-Control: s-maxage=86400 # CDN cache for 1 day
Cache-Control: stale-while-revalidate=60 # Serve stale while refreshing
Cache-Control: immutable # Never changes
Combined Directives
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ETags for Validation
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Last-Modified
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Vary Header
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Next.js Caching
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Common Patterns
Static Assets
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HTML Pages
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API Responses
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Debugging
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Set appropriate TTLs, use ETags for validation, and leverage stale-while-revalidate for better UX.