API Tester Playground
Test REST APIs, bypass CORS, and inspect JSON responses instantly.
Request Configuration
Response
What is this Free API Testing Tool?
The API Tester Playground is a free online API tester that lets developers test REST APIs directly from their browser. It works as a lightweight Postman alternative, allowing you to send HTTP requests (GET, POST, PUT, DELETE, PATCH), inspect responses, and debug APIs in real time.
Unlike standard browser-based fetch tools that fail due to CORS (Cross-Origin Resource Sharing) restrictions, this free API testing tool uses a secure backend proxy. This allows you to successfully query and debug any public API instantly.
How to use the API Tester Playground
- 1Select the HTTP method (GET, POST, PUT, DELETE, etc.) from the dropdown.
- 2Enter the full URL of the API endpoint you want to test.
- 3Toggle the "Proxy Mode" on if testing a public API to bypass CORS, or off if testing a localhost API.
- 4Add any required request headers (like Authorization tokens) in the Headers tab.
- 5If making a POST or PUT request, enter your JSON payload in the Body tab.
- 6Click Send Request and instantly view the status code, response time, and formatted JSON output.
Key features
- CORS Bypass Proxy: Seamlessly test public APIs without fighting browser CORS policies.
- Direct Localhost Mode: Toggle proxy mode off to test local development servers (e.g., localhost:3000).
- Full HTTP Support: Test GET, POST, PUT, PATCH, and DELETE methods.
- Header & Body Configuration: Easily append Bearer tokens, custom headers, and JSON request bodies.
- Formatted Output: Automatically syntax-highlights and formats JSON responses for easy reading.
Frequently asked questions
Why do I need a CORS proxy?
Browsers strictly enforce CORS policies, blocking JavaScript from making requests to different domains unless the target server explicitly allows it. Our proxy makes the request from a Node.js server instead, which ignores browser CORS rules, allowing you to successfully inspect the response.
Can I test my localhost API?
Yes! Simply toggle "Proxy Mode" off. This forces the request to originate directly from your browser rather than our server, allowing it to reach your local machine (assuming your local API allows CORS from our domain, or you are using a CORS-bypassing browser extension).
Are my API keys and tokens logged?
No. The proxy simply forwards your request directly to the destination and streams the response back. We do not store, log, or persist any of your headers, body payloads, or API responses.
Is there a limit on file uploads?
Yes. When sending multipart/form-data requests with file attachments, individual files are limited to 1MB in size to keep the proxy fast and responsive.
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