Encyclopedia / Hosting & delivery

Caching

Reusing a saved copy instead of fetching or rebuilding it.

The Cache-Control header tells browsers and CDNs how long they may reuse a response. Fingerprinted assets (style.3f9a.css) can be cached forever, because a new version gets a new name. HTML usually revalidates on every visit so updates show up right away.

Cache-Control: public, max-age=31536000, immutable   # hashed assets
Cache-Control: public, max-age=0, must-revalidate     # HTML

Related terms

CDN HTTP Performance

Where it shows up in a page load

  1. Step 4: HTTP request. The browser sends GET /work with headers: which languages it accepts, which compression it understands and any cookies. The edge checks its cache.

Watch the full request journey →

More in Hosting & delivery

Where the files live and how they reach a visitor quickly.

Web server / host CDN Edge Static site Dynamic site Serverless function Redirect Status codes

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