Free Online REST API Client
Use this basic online REST API client to send HTTP requests directly from the browser.
How To Use This Online REST API Client
This client is deliberately simple. Type any HTTP method, enter any URL, add headers, edit the request body, then send the request and inspect the status, response headers, and response body.
It does not check API Challenges expected results, does not restrict the URL to this site, and does not limit you to a practice mode path. The browser itself still applies browser security rules.
If this is your first time using a REST client, consider following How to Test REST APIs or the API Simulator Walkthrough first. Those tutorials explain the request and response flow, common HTTP methods, headers, payloads, and how to observe the results of exploratory API testing.
Use Browser Dev Tools To Help Test REST APIs
When you send requests from this browser REST client, open your browser developer tools and use the Network tab to see the raw HTTP requests and responses. The Network tab shows the request method, URL, headers, payload, status code, response headers, response body, redirects, timing, and any browser-level failures.
Browser developer tools are useful when a REST API request does not behave as expected because they show what the browser actually sent and received. You can compare the Network tab details with the response shown in this online client, or use them to debug headers, CORS failures, redirects, authentication problems, and unexpected content types.
Most browsers also let you export the captured Network session as a HAR file. A HAR file records HTTP Archive data for the requests in the session, so you can keep evidence of your API testing and later import or inspect the traffic in other tools.
CORS Limits For Browser REST API Clients
Because this client runs in the browser, it is limited by CORS.
CORS means Cross-Origin Resource Sharing. It is the browser rule that controls whether JavaScript from one origin can call another origin. If the API you call does not allow this site, the browser may block the request, block a preflight request, or hide parts of the response from JavaScript.
If a request works in cURL, Bruno, Postman, or another desktop client but fails here, check the browser developer tools console and network tab for CORS messages.
What You Can Test With An Online HTTP Client
Use this online HTTP client for quick exploratory API testing:
- send
GET,POST,PUT,PATCH,DELETE,OPTIONS,HEAD,QUERY, or another custom method - add custom request headers
- send JSON, XML, form data, plain text, or deliberately malformed payloads
- call same-origin API Challenges endpoints or external APIs that allow browser calls
- copy the generated cURL or wget command when you want to repeat the request outside the browser
The HTTP Basics, HTTP Verbs, and REST API Basics reference pages can help you decide which method, headers, status codes, and payload variations to try.
If you are starting from an OpenAPI file, use the OpenAPI Converter or Online Swagger UI to create starter requests, then come back to this Basic Client when you need fewer restrictions.
When To Use A Desktop REST API Client
A browser client is convenient for fast checks and learning, but desktop API clients and command line tools are still useful.
Use a desktop client when you need to avoid CORS limits, configure a proxy, send browser-blocked methods such as TRACE, manage large collections, or keep detailed testing evidence across sessions. Start with the REST/HTTP Clients overview, compare the summary reviews, or read the detailed reviews for Bruno, cURL, Postman, and Yaak.
For deeper investigation, use an HTTP proxy alongside your REST client so you can inspect the raw traffic and keep stronger evidence of what your API testing sent and received.