What does idempotent mean for an HTTP method?

An idempotent method produces the same server state whether you send the request once or many times. GET, HEAD, PUT and DELETE are idempotent; POST and PATCH are not, because repeating them can create duplicates or compound changes.

Which HTTP methods are safe?

Safe methods are read-only and must not change server state: GET, HEAD, OPTIONS and TRACE. POST, PUT, PATCH, DELETE and CONNECT are not safe because they are intended to cause effects.

What is the difference between PUT and PATCH?

PUT replaces a resource entirely with the body you send and is idempotent. PATCH applies a partial modification and is not idempotent, because repeated patches (for example "add 1") can keep changing the resource.

When should I use POST versus PUT?

Use POST to create a resource when the server assigns the identifier, or for non-idempotent actions. Use PUT to create or replace a resource at a URL the client already knows, where sending it twice has the same result.

Are GET requests cacheable?

Yes. GET and HEAD responses are cacheable by default, which is why they should never change server state. POST responses are only cacheable with explicit freshness headers, and that is uncommon.

Is this reference loaded from a server?

No. The full table and the search run entirely in your browser — nothing is fetched and nothing you type is uploaded.

HTTP Methods Reference

HTTP methods reference

A quick, searchable table of the HTTP methods defined by RFC 9110 — GET, HEAD, POST, PUT, PATCH, DELETE, OPTIONS, TRACE and CONNECT — and the properties that matter when designing an API. It is a fast way to settle “is this idempotent?” and “can I cache this?” questions while building REST endpoints.

How it works

Each method has four properties drawn from RFC 9110. Safe means read-only — it must not change server state. Idempotent means sending the request once or many times leaves the same state. Cacheable means the response may be stored and reused. The body column says whether the method normally carries a request body. Typing in the search box filters the table by method name or by a property keyword such as idempotent or preflight.

Example

The core methods compare like this:

Method	Safe	Idempotent	Cacheable	Typical use
GET	Yes	Yes	Yes	Read a resource
HEAD	Yes	Yes	Yes	Headers only, no body
POST	No	No	Rarely	Create / submit
PUT	No	Yes	No	Create or replace
PATCH	No	No	No	Partial update
DELETE	No	Yes	No	Remove a resource

Search by method name or by a property like idempotent to filter the table. Everything runs in your browser; nothing is uploaded.