A deep HTTP reference for developers
AG HTTP is a free developer reference for looking up HTTP status codes, methods, and headers in one place. It is not a bare list — every entry comes with real request/response examples, code snippets in popular languages, and troubleshooting.
The 62 status codes cover meaning, when they happen, common causes, step-by-step fixes, and related codes and headers. The 9 methods explain safety, idempotency, and cacheability with real examples, and the header dictionary gives syntax, directives, and security notes. For concepts, read the in-depth guides on REST design, caching, CORS, auth, and redirects.
All content is bundled statically in the browser and never sends anything to a server. Code names and technical terms stay in their canonical English form, while explanations are provided in Korean and English.
HTTP reason phrases (OK, Not Found) and header names (Cache-Control) are English by RFC spec and are the convention for developer references. Explanations and guides are provided in Korean and English, but code names and technical identifiers stay in canonical English.
401 Unauthorized means 'not authenticated' — login or credentials are required. 403 Forbidden means you are authenticated but lack permission; re-logging in will not help. See the authentication guide for details.
A safe method does not change server state (GET, HEAD). An idempotent method leaves the same final state no matter how many times it is sent (GET, PUT, DELETE). POST is neither, so retries can create duplicates — use an idempotency key.
No. All data is bundled statically in the browser, and nothing — including your search terms — is sent to or stored on a server.