Digital Lexicon Hub

The application-layer protocol used for request-response communication between clients and servers on the web.

HTTP behavior affects page speed, caching, security, API reliability and how search engines interpret redirects and errors, so it underpins decisions about site migrations, integrations and hosting.

During a domain migration, a developer maps 3,200 old URLs to new ones with 301 redirects, sets Cache-Control headers on static assets, and confirms that removed pages return 410 rather than a 200 status.

HTTP itself is stateless and unencrypted, so sessions rely on cookies or tokens and confidentiality requires HTTPS over TLS. Misused status codes, such as soft 404 pages returning 200, confuse clients and search crawlers.

A client sends a request with a method such as GET, POST, PUT or DELETE, a target URL, headers and an optional body, and the server returns a status code, headers and content. Status codes fall into five classes: 1xx informational, 2xx success, 3xx redirection, 4xx client error and 5xx server error. Semantics are defined in RFC 9110, while HTTP/1.1, HTTP/2 and HTTP/3 differ in how messages are framed and transported.