HTTP Safe and Idempotent Methods [RFC 2616]

Feb 14, 2020 RFC

All HTTP methods can be classified as safe or/and idempotent.

Method Definitions


The Host request-header field MUST accompany all HTTP/1.1 requests.

Safe and Idempotent Methods

Safe Methods


In short words: GET and HEAD SHOULD NOT cause any side-effects.

Idempotent Methods


Consider this:

  1. Use the DELETE method.
  2. The server deletes the resource.
  3. Use the same DELETE as in 1.
  4. The server cannot delete already gone resources. The server stays in the same state. You can repeat the same action, and the server still stays in the current state.