Long-lived caching makes repeat visits faster, but only when a changed file receives a new URL. Hashed JavaScript and CSS filenames are designed for that model; HTML usually needs a shorter freshness window.

Match the policy to the file

  • Fingerprint static assets and serve them with a long max-age plus immutable.
  • Let HTML revalidate or expire quickly enough that deployments can update page content.
  • Avoid applying a long immutable policy to filenames that are overwritten in place.
Cache-Control: public, max-age=31536000, immutable

Verify the response, not the config

After deployment, inspect the headers on both a hashed asset and an HTML page. A configuration file can be ignored, overridden, or cached by an upstream CDN.

Good caching supports performance and reliable releases. It does not change indexing directly, but a fast and stable site is easier for people to use.