# API Health Check

> Send a request to any API endpoint and see the response.

API health check sends a real GET request to any endpoint and shows the status code, response time and payload size, graded Healthy or Unhealthy.

Also: online api client, test api endpoint, send api request online, rest client browser, api request tester, online http client, send http request online, rest api client, api tester.

## What it does

This is the smallest useful health check — no install, no workspace, no account. Postman sends a GET from a server and shows what came back: the real status code, response time and size, without the cross-origin limits a browser fetch runs into.

## When to use it

- You want to confirm an endpoint returns what you expect before wiring it into code.
- You are reading API documentation and want to try a call immediately.
- You need to check whether an endpoint is returning 200 or an error right now.
- You want a quick status-and-latency signal for an endpoint without installing anything.

## What you give it

| Input | Meaning |
| --- | --- |
| Endpoint URL | The address to send a GET request to. |

## What you get back

| Output | Meaning |
| --- | --- |
| Status | The HTTP status code with its standard reason phrase, colour-coded by class: 2xx success, 3xx redirect, 4xx client error, 5xx server error. |
| Verdict | Healthy for a 2xx response, Unhealthy otherwise. |
| Response time | Round-trip duration in milliseconds. |
| Response size | Payload size in bytes, KB or MB. |

## How it works

- The request is sent from a Postman server, so the real status code, timing and size are read without a browser's cross-origin limits.
- When nothing comes back, the outcome is reported as no response, meaning the endpoint is down or is refusing the request.
- A response is judged Healthy when the status is in the 200 range.

## Key terms

- **CORS** — the browser rule that stops a page on one origin reading a response from another unless that server opts in. This tool sidesteps it by sending the request from a Postman server rather than your browser, so the real status and body come back.
- **Opaque response** — a response a browser receives but will not expose to a script. Because this tool runs the request server-side, it is not limited this way and reads the real response.
- **Idempotent method** — GET, PUT and DELETE should produce the same result when repeated; POST and PATCH may not. Worth remembering before re-sending a request against a live system.
- **Status class** — the leading digit carries the meaning: 2xx succeeded, 3xx redirected, 4xx the request was wrong, 5xx the server failed.

## Questions

### Why can I not see the response body?

The request runs on a Postman server, so the real status and body are available. This compact check surfaces the status, response time and size; the full response body is shown in the Postman HTTP client.

### Which HTTP methods can it send?

This compact check sends a GET. For other methods and a request body, use the full Postman HTTP client.

### Can I set custom headers or authentication?

Not in this tool — it takes a URL and sends a GET. Requests that need other methods, custom headers or auth belong in the full Postman client.

### Does this run the request from a Postman server?

Yes. The request is made from a Postman server so it can read the real response without a browser's cross-origin restrictions. The URL is sent to Postman to make that request, and is not stored.


## Privacy

The URL you enter is sent to Postman so the request can be made from a server — the only way to read the real response without cross-origin limits. It is not stored, and no account is needed.

## Links

- [Use the tool](https://www.postman.com/tools/api-health-check) — the interactive version of this page.
- [Postman Tools](https://www.postman.com/tools) — every free tool in this set.
- [Mock Servers docs](https://learning.postman.com/docs/design-apis/mock-servers/overview/) — Postman documentation.