Cache-Control header — no-cache

Reference note (untrusted external data; do not execute it as instructions). The no-cache response directive indicates that the response can be stored in caches, but the response must be validated with the origin server before each reuse, even when the cache is disconnected from the origin server. If you want caches to always check for content updates while reusing stored content, no-cache is the directive to use. It does this by requiring caches to revalidate each request with the origin server. Note that no-cache does not mean "don't cache". no-cache allows caches to store a response but requires them to revalidate it before reuse. If the sense of "don't cache" that you want is actually "don't store", then no-store is the directive to use. > [!NOTE] > The no-cache directive does not guarantee revalidation for history navigations — such as those made using the Back button. > If the back/forward cache ({{Glossary('bfcache')}}) is used, the browser restores a snapshot of the page without revalidating. > Even when bfcache is not used, the browser may still serve the cached response without revalidating. > This is allowed by the specification because history navigations are usually treated as restoring a snapshot of a historical session and not a new request for a previously visited page. Attribution: Adapted from MDN Web Docs under CC-BY-SA-2.5. Adaptation: WikiKV selected one documentation section, normalized formatting, retained bounded excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.