API Request Builder — In-Browser HTTP Client
Build and send HTTP API requests directly from your browser. Set method, URL, query params, headers, and body (JSON, raw, or form-encoded). View the response status, headers, and body — and copy an equivalent cURL command for terminal use. Free, browser-based, no proxy.
How to Use API Request Builder — In-Browser HTTP Client
How to Use the API Request Builder
Step 1: Select the HTTP Method
Click the method dropdown and choose from GET, POST, PUT, PATCH, DELETE, HEAD, or OPTIONS. The dropdown is color-coded by method for quick identification.
Step 2: Enter the URL
Type or paste the full URL including the protocol (https://). The URL must be publicly accessible from your browser — private network endpoints may not be reachable.
Step 3: Add Query Parameters (optional)
Click the Params tab to add key-value pairs. Each enabled pair is appended to the URL as a query string. You can see the resolved URL preview below the URL input when params are present.
Step 4: Set Headers (optional)
The Headers tab shows pre-filled Content-Type and Accept headers. Add, edit, or disable any header. Use the checkbox to enable or disable a header without deleting it.
Step 5: Set the Request Body (optional, POST/PUT/PATCH/DELETE)
Go to the Body tab. Choose a body mode:
- JSON — paste or type a JSON object. Ensure Content-Type is set to application/json.
- Raw — plain text or any string body.
- Form URL Encoded — add key-value fields that are sent as application/x-www-form-urlencoded.
Step 6: Send the Request
Click Send or press Enter in the URL field. The request is sent directly from your browser via fetch(). The response panel shows the HTTP status code, duration, body, and response headers.
Step 7: Copy the cURL Command
The cURL panel is always visible once you enter a URL. Click Copy cURL to copy the exact equivalent curl command. Run it from your terminal to replay the request without browser CORS restrictions.
Step 8: Inspect the Response
Use the response tabs:
- Body — the formatted response body. JSON is pretty-printed automatically.
- Headers — all response headers returned by the server.
- cURL — the cURL equivalent of the request you just sent, with all headers and body included.
Common Use Cases:
- API development: Test endpoints while building your backend, before connecting a frontend client
- Debugging integration issues: Reproduce a failing API call with exact headers and body
- Exploring public APIs: Send GET requests to public APIs to inspect the response structure
- Generating cURL commands: Build a request visually and export it as a cURL command for documentation or sharing
- Testing auth headers: Add Authorization or API-Key headers and verify the server accepts them
- Form submission testing: Use Form URL Encoded mode to test HTML form-handling endpoints
Tips and Best Practices:
- Use the cURL command to bypass CORS when testing APIs that block browser requests
- Disable a header by unchecking it instead of deleting it — so you can re-enable it later
- Query params added in the Params tab are URL-encoded automatically
- The cURL panel updates in real time as you modify the request — no need to send first
- For APIs that require OAuth tokens, paste the Bearer token directly in the Authorization header value
Frequently Asked Questions
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