API Tester

The API Tester lets you compose and send HTTP requests from your browser: enter a URL, choose a method, optionally add headers and a body, and inspect what comes back. It is a quick way to check whether an endpoint is reachable and to try out a request before you put it into code or a dedicated API client.

The workspace offers GET, POST, PUT, and DELETE method buttons, a URL field, a Headers field that accepts JSON, and a Body field for request payloads.

How to Use the API Tester

1. Open the API Tester page in your browser.
2. Type or paste the full endpoint URL, including https:// or http://.
3. Choose a method: GET, POST, PUT, or DELETE.
4. If the endpoint needs headers (for example, Content-Type or an Authorization token), enter them as JSON in the Headers field.
5. If you are sending data, enter it in the Body field.
6. Click Process and read the result panel.

Worked Example

Request: GET https://jsonplaceholder.typicode.com/todos/1, with no headers and no body.

Output observed on this page: the result panel showed only an informational note — “Testing APIs from the browser is limited by CORS. Server-side proxy is recommended for full API testing.” It did not return the todo item’s JSON (which would normally be {"userId": 1, "id": 1, "title": "delectus aut autem", "completed": false}).

In other words, the tool currently explains the browser’s CORS limitation instead of displaying the API response. Confirm any result with a dedicated client such as curl or Postman before relying on it.

Limitations

• The tool did not return an actual API response in testing. A GET request to a public, CORS-enabled test API produced only the CORS informational note, not a status code, headers, or body.
• Browsers enforce CORS: a page can only read a cross-origin response if the API sends the right Access-Control-Allow-Origin headers. This tool has no server-side proxy to work around that.
• There is no visible control for PATCH, HEAD, or OPTIONS methods, timeouts, or saving request history.
• Do not paste real secrets or production API keys into this tool. Requests run from your browser, and anything you enter could be exposed in browser history, logs, or the network.

Frequently Asked Questions

Why do I not see the API response?

Most likely CORS: the browser blocks the page from reading the response unless the API explicitly allows it. In our test, the tool showed a CORS note instead of the response even for a public test API.

Which HTTP methods does the tool support?

The workspace shows buttons for GET, POST, PUT, and DELETE.

Can I send a JSON body with a POST request?

Yes. Enter the payload in the Body field, and set a Content-Type: application/json header in the Headers field.

Can this replace Postman or curl?

No. Use this tool for quick, casual checks only. For real API development and debugging — full responses, status codes, authentication flows, and environments — use Postman, Insomnia, curl, or a similar dedicated client.