HTTP methods — GET POST PUT PATCH DELETE explained

HTTP Methods and Their Semantics

Choosing the wrong HTTP method is the most common REST design mistake. Each method carries a defined semantic contract that clients, caches, and proxies rely on.

Method Definitions

GET — Retrieve a resource. Safe and idempotent. Never modify state with GET.

POST — Create a resource or trigger an action. Not idempotent. Calling twice creates two resources.

PUT — Replace a resource entirely. Idempotent. Calling twice has the same result as calling once.

PATCH — Partially update a resource. Send only the fields that change.

DELETE — Remove a resource. Idempotent.

// PATCH — update only the email field
PATCH /users/42
Content-Type: application/json

{ "email": "alice@new.com" }

// PUT — replace entire user object
PUT /users/42
Content-Type: application/json

{ "name": "Alice", "email": "alice@new.com", "role": "admin" }

Idempotency Rule

An operation is idempotent when calling it N times produces the same result as calling it once. GET, PUT, DELETE, and PATCH are idempotent. POST is not. This matters for retry logic — safe to retry idempotent methods on network failure; dangerous to retry POST blindly.