API Tester

Client-Side New

Send HTTP requests (GET, POST, PUT, DELETE, PATCH) directly from your browser and inspect the responses. Add custom headers, JSON request bodies, and see formatted response data with status codes and timing. Great for quick API testing without leaving the browser. Note: browser CORS policies may affect some requests.

Note: Browser CORS policies may block some requests. Use a CORS proxy or test CORS-enabled APIs.

GETNo URL specified

Headers

How to Use

1

Enter the URL

Type or paste the API endpoint URL you want to test.
2

Configure the Request

Select the HTTP method, add headers (like Authorization or Content-Type), and enter a JSON body for POST/PUT/PATCH requests.
3

Send and Inspect

Click Send to execute the request. View the response status, timing, headers, and formatted body.

Examples by Niche

Public API

GET https://jsonplaceholder.typicode.com/posts/1 - Test a public REST API endpoint

POST Request

POST with JSON body {"title": "Test", "body": "Hello"} and Content-Type: application/json header

Authentication

Add Authorization: Bearer <token> header to test protected endpoints

Frequently Asked Questions

Why do some requests fail with CORS errors?

Browsers enforce CORS (Cross-Origin Resource Sharing) policies that block requests to APIs that do not explicitly allow browser-based access. This is a security feature. Use a CORS proxy or test from a backend environment for restricted APIs.

What HTTP methods are supported?

GET, POST, PUT, DELETE, and PATCH are supported. GET is used to retrieve data, POST to create, PUT to update, DELETE to remove, and PATCH for partial updates.

Is my request data stored or sent anywhere?

No, all requests are sent directly from your browser using the fetch API. Your data is not stored on any server. Request history is saved locally in your browser for convenience.

How do I add authentication headers to my requests?

Click "Add Header" and enter the header name (e.g., Authorization) and value (e.g., Bearer your-token-here). For Basic auth, use the format "Basic base64(username:password)". For API keys, check the API documentation for the correct header name, which is often X-API-Key or Authorization.

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API Tester

How to Use

Enter the URL

Configure the Request

Send and Inspect