API Tester
Build a request, send it, and read the response, all inside a single browser tab...Build a request, send it, and read the response, all inside a single browser tab. Supports every standard HTTP method with custom headers, authenticat...
Updated
Press Ctrl+Enter to send
One per line, Key: Value
Common Status Codes
At a Glance
Why Use API Tester?
Open a Tab and Start Testing
There is no binary to download, no account form to fill out, and no workspace to configure. The moment the page loads, you can paste a URL and send your first request. That makes it perfect for those situations where you need a quick answer from an endpoint and do not want to wait for Postman to boot up.
All Seven Standard HTTP Methods
GET, POST, PUT, PATCH, DELETE, HEAD, and OPTIONS sit behind clearly labeled buttons with distinct color coding. Green for GET because you are reading data, blue for POST because you are creating something, red for DELETE because it is destructive. The colors help you avoid clicking the wrong method when you are moving fast.
Automatic JSON Detection and Formatting
When the response body contains valid JSON, the tool detects it and renders a properly indented, syntax-highlighted view. If the response is plain text, HTML, or XML, it appears as raw text so nothing gets swallowed or reformatted unexpectedly. You see exactly what the server returned.
Timing That Catches Slow Endpoints Early
The clock starts the moment your browser dispatches the request and stops when the last byte arrives. You get the round-trip time in milliseconds alongside a label, Fast under 200ms, Normal under a second, Slow beyond that. Compare the same endpoint across staging and production to spot regressions before they reach users.
Headers and Authentication Without Friction
Type headers in a simple Key: Value format, one per line. Bearer tokens, API keys, Basic auth credentials, custom X-headers, whatever the endpoint demands. No dropdowns that hide options, no modals that break your flow, and no forced content types unless you set them yourself.
Replay Past Requests in One Click
The last ten requests are persisted in your browser so you can revisit them without retyping anything. Each entry shows the method, URL, status code, and response time. Click one and the entire form repopulates, URL, headers, body, everything, so you are back to where you left off instantly.
Who Reaches for This Tool
Isolating Frontend Bugs
When a screen shows the wrong data, the question is whether the API returned the wrong payload or the frontend mishandled a correct one. Sending the same request through this tool and comparing the raw response to what your code renders narrows the problem down in minutes rather than hours of stepping through code.
Validating Third-Party Integrations Before Writing Code
Documentation sometimes lags behind reality. Before you commit to wiring up a third-party API into your application, send a few exploratory requests here to confirm the actual response structure, required headers, rate limit behavior, and error message format match what the documentation claims.
Hands-On Learning for New Developers
Reading about HTTP methods, status codes, and headers in a textbook is passive. Firing real requests against a live API and watching how different methods, malformed payloads, and missing tokens produce different outcomes turns abstract concepts into memorable experience.
Triggering Webhooks Manually
Instead of waiting for an upstream service to fire a webhook event, send a POST to your handler with the expected payload shape. Verify that the handler parses the data, stores it correctly, and returns the right status code, all in one request cycle without setting up mock servers or replay infrastructure.
How It Works
Choose a Method and Paste the URL
Tap the method that matches your intent, GET to retrieve a resource, POST to create one, PUT or PATCH to update, DELETE to remove, HEAD to check existence, OPTIONS to inspect CORS. Then type or paste the full URL including the protocol.
Add Headers and Write the Body
Enter any required headers like Authorization or Accept on separate lines. If you chose POST, PUT, or PATCH, the body editor activates for you to write or paste a JSON payload. For GET, DELETE, HEAD, and OPTIONS the body editor stays disabled because those methods carry no request body by convention.
Send the Request and Inspect the Response
Press the Send button or use the keyboard shortcut Ctrl+Enter on Windows and Cmd+Enter on Mac. The response panel appears with the status code, latency, payload size, fully formatted body, and every response header the server sent back. Copy the body to your clipboard or replay the request from history whenever you need it again.
Developer Tips
Try the Sample Requests First
The quick-start buttons send real requests to JSONPlaceholder, a free mock API. They show you the full request-response cycle in seconds and help you understand the interface before you point it at your own endpoints.
Keyboard Shortcut Saves Real Time
Press Ctrl+Enter on Windows or Cmd+Enter on Mac from anywhere in the form to dispatch the request. During a debugging session where you are modifying the body and resending repeatedly, this shortcut eliminates dozens of mouse movements over the course of an hour.
CORS Errors Are Not Tool Failures
A network error without a status code almost always means the target server does not include CORS headers. That is the server rejecting browser-based requests, not a bug in this tool. The fix is to add CORS headers on your server or to use a backend tool like curl for servers you do not control.