What are Idempotent HTTP Methods?
What are Idempotent HTTP Methods?
In HTTP, an idempotent method is one that produces the same result on the server, no matter how many times it is executed. Repeated requests should not change the resource state beyond the first request.
Idempotent HTTP Methods
- GET: Retrieves data without modifying the resource. Multiple requests return the same result.
- HEAD: Similar to GET but only retrieves headers, making it idempotent.
- PUT: Updates or creates a resource. Repeated requests ensure the resource remains unchanged.
- DELETE: Removes a resource. Multiple requests have the same effect as one. PUT and DELETE are idempotent but modify resources.
- OPTIONS: Retrieves supported HTTP methods without modifying the resource.
Non-Idempotent HTTP Methods
POST and PATCH are not idempotent as repeated requests can yield different effects.
- POST: Creates resources or submits data. Multiple requests can create duplicates.
- PATCH: Partially updates a resource. The outcome may differ on repeated requests.
Idempotent methods ensure the same result, even when repeated. Safe methods like GET and HEAD do not modify resources and are idempotent.
