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Free REST API Tester Online

Test REST APIs directly from your browser. Send GET, POST, PUT, DELETE requests with custom headers and body payloads.

Last Updated: July 2026

Why Use Our Free API Tester?

Test REST APIs directly from your browser. Send GET, POST, PUT, DELETE requests. As a developer, dealing with complex formatting, debugging, and data processing can be incredibly tedious. Our free online API Tester removes the friction from your workflow, allowing you to instantly process your data without installing heavy software or risking your proprietary code on insecure servers.

Features of Our Free API Tester

  • Instant Local Processing: All calculations and parsing happen instantly in your web browser.
  • 100% Privacy Guarantee: Your code and API payloads are never uploaded to our servers.
  • No Installation Required: Access the tool instantly from any modern web browser.
  • Completely Free: No premium features, no subscriptions, no paywalls.

How to Use Input Your Data Online Free

Using Input Your Data is straightforward:

  1. Initialize Input Your Data: Access the interface and enter your specific parameters to begin the process.
  2. Configure Options: Select any necessary output formats or preferences tailored to your task.
  3. Execute Process: Run the tool to Test REST APIs directly from your browser. Send GET, POST, PUT, DELETE requests with custom headers and body payloads.
  4. Review Output: Once processing is complete, export or copy the generated results directly to your clipboard.

What is an API Tester?

An API (Application Programming Interface) Tester is a tool that allows developers to send HTTP requests to servers and view their responses. It simulates the behavior of a frontend application or a backend service communicating with an API.

Our web-based API tester lets you send standard requests (GET, POST, PUT, DELETE, PATCH) right from your browser, making it incredibly fast to verify endpoint functionality.

Important Note on CORS

Because this tool runs inside your browser via the Fetch API, it is subject to Cross-Origin Resource Sharing (CORS) policies.

If you attempt to request an API that does not explicitly allow your browser to fetch it from our domain, the browser will block the request for security reasons. To test such APIs, you will need a dedicated desktop client like Postman or Insomnia, or you must enable CORS on your backend server during local development.

Supported Methods

  • GET: Retrieve data from the server.
  • POST: Send new data to the server (requires a body).
  • PUT: Replace existing data on the server.
  • PATCH: Partially update existing data.
  • DELETE: Remove data from the server.

Frequently Asked Questions About Free REST API Tester

Is my proprietary code or data stored on your servers?

No, absolutely not. This tool operates entirely on the client-side within your web browser. Your code, API keys, and data payloads are never transmitted, uploaded, or stored on our servers, ensuring 100% data privacy.

Can I use this tool on a mobile device?

Yes! Our platform is fully responsive and optimized for mobile devices, allowing you to use this tool seamlessly on your smartphone or tablet.

Is there a limit to how much data I can process?

Because the processing happens locally in your browser, the only limit is your device's memory. You can generally process large payloads without any performance issues.

Do I need to install any software or extensions to use this?

No installation is required. You can access and use the tool instantly from any modern web browser.

Is this tool completely free?

Yes, this tool is 100% free to use with no hidden fees, subscriptions, or premium features locked behind a paywall.

What HTTP methods are supported by this API Tester?

Our API Tester supports all standard HTTP methods, including GET, POST, PUT, DELETE, PATCH, and OPTIONS, allowing you to fully test your RESTful endpoints.

Can I add custom headers to my API requests?

Yes, you can easily add custom headers, such as Authorization tokens, Content-Type, or any custom API keys required by your server.

How does this tool handle CORS errors?

Because this is a web-based tool, making requests directly from your browser to external domains might trigger CORS blocks. We utilize a secure backend proxy to bypass these restrictions so you can seamlessly test any API.

Can I send JSON payloads in my POST requests?

Absolutely. The tool provides a dedicated request body editor where you can write and send raw JSON, form data, or plain text payloads.

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