REST API Checker
Test any REST API endpoint directly from your browser. Send GET, POST, PUT, DELETE, PATCH, HEAD or OPTIONS requests with custom headers and JSON, raw or multipart body — including file uploads. View the response status, headers, timing and formatted body in one screen.
About the REST API Checker
REST APIs are the backbone of modern web and mobile applications — they expose data and operations over HTTP so different systems can talk to each other. Whether you are integrating a payment processor, consuming a public weather API, building a mobile backend, or debugging a third-party webhook, you need a fast way to send requests and inspect the response without writing any code.
This online REST API Checker is a free browser-based alternative to desktop clients like Postman, Insomnia, or command-line tools like cURL. It supports every standard HTTP method (GET, POST, PUT, DELETE, PATCH, HEAD, OPTIONS), arbitrary request headers, and three common body formats: JSON (for typical REST and GraphQL APIs), raw (for XML, plain text, or any custom content type), and multipart form-data (for file uploads or traditional form posts).
Requests are made server-side, which means you are not blocked by browser CORS policies — you can test any public HTTPS API regardless of its CORS configuration. The response is returned with the full status line, headers, body, timing, and size so you can quickly verify behaviour, debug failing integrations, test authentication tokens, or learn how an unfamiliar API works. Private and loopback IP ranges are blocked for security.
Frequently Asked Questions
Access-Control-Allow-Origin. This tool makes the request from our server, which is not subject to CORS — so you can test any public API regardless of its CORS configuration.Authorization with the value Bearer YOUR_TOKEN (for OAuth/JWT), Basic base64(user:pass) (for HTTP Basic), or your API's custom scheme like ApiKey abc123. Some APIs use a different header name like X-API-Key or X-Auth-Token — always check the API docs for the exact name and prefix.Authorization header is exactly what the API expects — correct prefix (Bearer vs Basic), no extra spaces, and not URL-encoded. 401 means "who are you?", whereas 403 means "I know who you are, but you can't do this".Content-Type, missing required fields, or values outside the expected types. Try copying the exact example from the API docs first to confirm the endpoint works, then modify one field at a time.Access-Control-Allow-Origin matching your origin. If it doesn't, you need to either ask the API provider to allow your domain, or proxy the call through your own backend (which is what this tool does internally for testing). Server-to-server calls never trigger CORS — it's a browser-only restriction.About This REST API Checker
This server-side REST API checker sends HTTP requests (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS) from our server to any URL, returning the status code, response headers, response body, and latency. Because the request is proxied server-side, CORS restrictions do not apply.
Unlike browser-based request tools, server-side proxying lets you test APIs that block cross-origin requests, reach internal staging endpoints, and inspect raw response headers exactly as the server sends them — without installing any software.
When to use this tool
- Testing API endpoints without setting up a local HTTP client
- Debugging CORS or authentication header issues
- Inspecting redirect chains and raw response headers
- Verifying webhook endpoints and health-check URLs
Standards & References
How it works
Three steps happen every time you click Send:
Build your request
Enter a URL, pick a method, add headers (e.g. Authorization: Bearer …), and choose a body format — JSON, raw text, or multipart with file upload.
Server proxies the call
Your browser sends the request specification to our server, which makes the actual HTTP call using cURL with TLS verification enabled — bypassing CORS restrictions.
Inspect the response
See the status code, response time, body size, all response headers and the response body — automatically pretty-printed if the body is valid JSON.
Common Use Cases
API integration testing
Verify a third-party API works as documented before writing integration code. Catch undocumented quirks (extra fields, unexpected status codes) early.
Debug failing webhooks
Replay a webhook payload to reproduce a 4xx/5xx error and inspect exactly what the receiver sees, including response headers.
Test authentication
Verify API keys, OAuth bearer tokens, Basic auth or signed requests against a protected endpoint before wiring them into production code.
Learn an unfamiliar API
Explore endpoints, response shapes and error formats interactively before reading the full documentation. Faster than writing code first.
Compare endpoints
Quickly switch between staging and production URLs to compare response payloads side by side and catch environment drift.
Upload file via multipart
Test file-upload endpoints by attaching a file in the multipart body and observing the response — useful for image uploads, document import APIs, etc.
