API Tester
Send HTTP requests and inspect responses
Headers
Request headers
Continue with
Keep the workflow moving with a closely related next action.
Privacy & Trust
CORS still applies
Requests are sent from the browser, so cross-origin rules and missing `Access-Control-Allow-Origin` headers can block calls even when the endpoint is healthy.
Do not paste production secrets
Authorization tokens, private cookies, and internal endpoints should be tested with proper local tooling or server-side proxies instead of a public browser session.
Session-level visibility
This tool only shows what the browser receives. It does not expose server logs, redirect traces beyond fetch behavior, or privileged network details.
Export response
Send a request before exporting anything.
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How to Use
Open the Tool
No setup needed — the tool loads instantly in your browser.
Interact and Explore
Use your mouse, keyboard, or touch to interact in real time.
Use Anytime, Anywhere
Works on desktop and mobile — practice or create on the go.
Why Use This Tool
100% Free
No hidden costs, no premium tiers — every feature is free.
No Installation
Runs entirely in your browser. No software to download or install.
Private & Secure
Your data never leaves your device. Nothing is uploaded to any server.
Works on Mobile
Fully responsive — use on your phone, tablet, or desktop.
API Testing: Validating RESTful Web Services
Key Takeaways
- REST APIs use standard HTTP methods: GET (read), POST (create), PUT (update), DELETE (remove).
- HTTP status codes indicate results: 2xx = success, 4xx = client error, 5xx = server error.
- API testing should verify response status, body content, headers, and performance under load.
API testing validates that web services accept requests and return correct responses. RESTful APIs, the most common architecture for web services, use standard HTTP methods and return data typically in JSON format. Whether you are building, integrating, or debugging APIs, a good testing tool is essential for verifying endpoints work correctly.
REST
Most common API architecture
Common Use Cases
Endpoint Validation
Test that each API endpoint returns the expected response format, status code, and data.
Integration Testing
Verify that third-party APIs you integrate with behave as documented.
Debugging
Diagnose issues by inspecting raw request/response headers and body content.
Documentation Verification
Ensure API documentation matches actual endpoint behavior and response formats.
Practical Tips
Test all HTTP methods (GET, POST, PUT, DELETE) and verify both success and error responses.
Include edge cases: empty payloads, missing required fields, invalid data types, and very large inputs.
Save and organize your API tests as collections so they can be rerun after code changes.
Check response time — an API that returns correct data but takes 10 seconds is still broken for users.
This tool is for informational and educational purposes. Verify results before using in critical applications.