HTTP topic
HTTP caching
HTTP caching is a coordinated decision about storing and reusing responses. Follow the material here from the core freshness model into validators, directives, shared caches, CDN behavior, and stale-response diagnosis.
Recommended foundation
Start here
This entry establishes the shared model used by the references, diagnostics, and experiments below.
Learn
Understand HTTP caching and validation
Follow the decisions a cache makes from storage through freshness and validator-based reuse.
HTTP caching
Learn
1 reviewed entry
HTTP caching
Reference
7 reviewed entries
intermediate
304 Not Modified
A 304 response confirms that a conditional request can reuse its stored representation.
intermediate
Cache-Control field
Cache-Control carries case-insensitive directives that constrain caching and reuse.
intermediate
ETag field
ETag carries an opaque validator for the selected representation.
intermediate
max-age cache directive
Response max-age defines a freshness lifetime in seconds from response generation.
intermediate
no-cache cache directive
no-cache requires validation before reuse; it does not mean do not store.
intermediate
QUERY method
QUERY asks a target resource to process enclosed query content safely and idempotently and return the result.
intermediate
Vary field
Vary tells recipients which request fields influenced representation selection.
HTTP caching
Troubleshoot
2 reviewed entries
HTTP caching
Lab
2 reviewed entries
HTTP caching
Glossary
2 reviewed entries
HTTP caching
HTTP History
2 reviewed entries
intermediate
HTTP/1.0: when the growing Web needed real messages
HTTP/1.0 documented the message features implementations had added as the Web expanded beyond retrieving HTML documents.
intermediate
HTTP/1.1: persistent connections and the architecture of scale
HTTP/1.1 made connection reuse, virtual hosting, precise framing, richer caching, and intermediaries work at Web scale.