HTTP Request Methods Explained: GET, POST, and the Rest

Every HTTP request carries a method that tells the server what kind of action the client wants to perform. Browsers, APIs, and uptime monitors all rely on the same small set of methods, but each one signals something different — and picking the wrong one can quietly break your monitoring.

The core methods

• GET — Retrieves a resource without changing anything on the server. This is the method almost all uptime and status checks use: it's safe to repeat, cacheable, and side-effect free.
• POST — Submits data to create or trigger something, such as a form submission or a new record. Repeating a POST can create duplicates, so it's rarely used for routine health checks.
• PUT — Replaces a resource entirely with the data provided. Idempotent, meaning sending the same PUT twice has the same effect as sending it once.
• PATCH — Applies a partial update to a resource, changing only the fields included in the request.
• DELETE — Removes the specified resource.
• HEAD — Identical to GET, but returns only the response headers, not the body. Useful for lightweight checks that just need a status code.
• OPTIONS — Asks the server which methods and headers are allowed for a resource, often used by browsers during CORS preflight requests.

Why the method matters for monitoring

Most uptime checks default to GET or HEAD because both are safe — they won't accidentally submit a form, create a record, or trigger a workflow every time your monitor runs a check. If your monitoring tool lets you choose a method, GET is almost always the right default; reach for HEAD only when you want a faster check that ignores the response body.

Where this trips people up is API monitoring. If the endpoint you care about only responds to POST or PUT — for example, a webhook receiver or a login endpoint — a GET request to that same URL may return a 404 or 405 (Method Not Allowed) even though the service is perfectly healthy. In that case, your monitor needs to send the same method the real clients use, ideally with a harmless payload, so the check reflects reality instead of a false alarm.

Idempotency, briefly

GET, HEAD, PUT, DELETE, and OPTIONS are idempotent — calling them multiple times has the same effect as calling them once. POST and PATCH generally are not. This distinction is why retries are safe to automate for idempotent methods but risky for the others; a monitoring system that automatically retries a failed POST could end up submitting the same data twice.

Understanding which method a given endpoint expects — and which one your monitor is actually sending — is one of the simplest ways to cut down on false positives and confusing alerts.