GET vs POST explained: safety, idempotency, caching, body semantics and when to use each HTTP method, with a complete request-method cheatsheet.
TL;DR: Free HTTP method cheatsheet covering GET, POST, PUT, DELETE, PATCH, and more. Annotates idempotency and safety, fully available offline.
For local tools, open DevTools → Network and search your input — it should not appear in requests.
Usage Guide
HTTP methods go beyond GET and POST: PUT versus PATCH, whether DELETE can carry a body, why idempotency matters — these details decide whether an API is correct. This page is a per-method cheat sheet with safety and idempotency annotated, plus usage notes.
1. Reading the cheat sheet
- Each method carries two key properties: safety (does it change server state) and idempotency (is repeating the request harmless).
- Click a method for details: semantics, body conventions, cache behavior, common misuse.
- Keep it at hand when designing: "is retrying this safe" decides PUT versus POST.
2. Two confusions worth settling
- PUT vs PATCH: PUT is full replacement (submit the complete new representation); PATCH is partial (only the changed fields). Updating a single field via PUT while omitting the rest is the classic data-loss bug.
- Why idempotency matters: clients retry on network timeouts — retrying GET/PUT/DELETE is harmless, but retrying POST may double an order. That is why payments and ordering need application-level idempotency keys, not a different method.
3. The forgotten methods
HEAD and OPTIONS are overlooked: HEAD returns headers without a body — cheaper than GET for probing size or existence; OPTIONS carries the CORS preflight, which is what the browser sends before a cross-origin request to ask "which methods and headers are allowed". When front-end debugging shows a failed OPTIONS before the error, that is the preflight failing, not your API.
FAQ
Yes. All method data is built into the page, so once loaded it works with no connection at all — searchable by method name or keyword. The page is an explanatory reference only and never fires real network requests.
GET, POST, PUT, DELETE, PATCH, HEAD, OPTIONS, CONNECT, and TRACE, each with a usage description plus annotations for safety, idempotency, cacheability, and request/response body support.
PUT is a full replacement — you submit the complete resource, and any fields you leave out are wiped. PATCH is a partial update — only the changed fields go in and the rest stay untouched. PUT is idempotent; PATCH is not guaranteed to be (per RFC 9110, it depends on the semantics).
Safe methods such as GET must not change server state — never mutate through a GET. Idempotent means repeating the call leaves the same result; DELETE is naturally idempotent, and repeated deletes should keep succeeding semantically. These labels decide whether your retry and caching strategies are safe to apply.
Gateways and frameworks may add their own constraints on bodies, caching, and CSRF. Browser forms lean naturally on GET and POST — the other verbs mostly live in API clients. Write team conventions (for example, "updates always use PATCH") into your API docs and test cases, and pair the page with the HTTP status-code cheatsheet, an API tester, and a JWT debugger.
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