API Tester — In-Browser REST Client
Test HTTP API endpoints directly in your browser. Make GET, POST, PUT, PATCH, and DELETE requests with custom headers and request bodies. View status codes, response headers, and pretty-printed JSON responses — all client-side, no server proxy.
How to Use API Tester — In-Browser REST Client
How to Use the API Tester:
Select HTTP Method: Choose GET, POST, PUT, PATCH, DELETE, or HEAD from the method dropdown.
Enter the URL: Type or paste the full endpoint URL including https://. Press Enter or click Send to dispatch the request.
Configure Headers: Open the Headers tab to add, edit, or disable request headers. Two defaults (Content-Type and Accept) are pre-filled — uncheck or remove them as needed.
Add a Request Body (POST/PUT/PATCH): Open the Body tab and enter your payload. Typically JSON:
{
"name": "Alice",
"email": "alice@example.com"
}
- Read the Response: The response panel shows the HTTP status code, duration in milliseconds, all response headers, and the body — automatically pretty-printed if it is valid JSON.
HTTP Methods:
- GET — Retrieve data. No body. Safe and idempotent.
- POST — Create a resource. Body required.
- PUT — Replace a resource. Full body required.
- PATCH — Partial update. Send only the fields to change.
- DELETE — Remove a resource. Usually no body.
- HEAD — Like GET but returns headers only. Useful for checking if a resource exists.
Common Request Headers:
- Content-Type: application/json — body is JSON
- Authorization: Bearer <token> — JWT or OAuth token
- X-API-Key: <key> — custom API key header
- Accept: application/json — request JSON response
CORS Limitations: Browsers enforce CORS policies. If the target API does not send appropriate CORS headers, your browser blocks the request. This is a browser security feature. For APIs that block browsers, use curl or Postman from your terminal instead.
Privacy: All requests are sent directly from your browser to the target server. Nothing passes through 100Plus Tools servers. URLs, headers, and bodies are not stored or logged.
Common Status Codes:
- 200 OK — request succeeded
- 201 Created — resource created
- 204 No Content — success, no body
- 400 Bad Request — invalid input
- 401 Unauthorized — authentication required
- 403 Forbidden — not allowed
- 404 Not Found — resource does not exist
- 422 Unprocessable Entity — validation failed
- 429 Too Many Requests — rate limited
- 500 Internal Server Error — server-side error
Frequently Asked Questions
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