API Test
Send HTTP requests, manage headers, query params, request bodies, saved endpoints, and response history from a browser-based API testing client.
What API Test Does
API Test is a free browser-based REST client for sending HTTP requests and inspecting responses without leaving your current workflow. It supports common methods such as GET, POST, PUT, DELETE, PATCH, HEAD, and OPTIONS, along with request headers, query parameters, request bodies, saved endpoints, and response history. That makes it useful for developers, QA teams, technical support, and API integrators who need a practical way to explore and debug endpoints quickly. API work often involves repeated small checks: confirming headers, testing payload changes, comparing status codes, validating error handling, or reproducing a bug reported by another team. A dedicated request client speeds up those checks by keeping all the moving pieces in one place instead of requiring scripts or repetitive terminal commands. This tool is especially helpful for ad hoc debugging and exploratory testing. You can build a request, send it through the proxy layer, inspect status and response data, and then adjust headers or parameters for the next iteration. Saved endpoints and history make repeated work easier, which is useful when troubleshooting staging environments or complex third-party integrations. It is not limited to backend engineers either. Product teams and support specialists often need to test an endpoint or verify that a service responds as documented. A browser UI lowers the barrier for that kind of technical collaboration. For day-to-day development, a lightweight API client is one of the most useful utilities you can have. This tool focuses on the practical essentials needed to test, inspect, and iterate on request-response workflows quickly.
Key Features
Multi-method request support
Send GET, POST, PUT, DELETE, PATCH, HEAD, and OPTIONS requests from one interface.
Headers, params, and body editing
Build realistic requests by controlling the main inputs most APIs depend on.
Saved endpoints and request history
Revisit previous requests quickly when debugging recurring integrations or staging environments.
Visual response inspection
Review status, payload, timing, and other response details without switching contexts.
Good for exploratory API debugging
Helps teams iterate on requests quickly while refining headers, payloads, and parameters.
Common Use Cases
Testing a new REST endpoint
Developers can verify request shape, response codes, and body handling before integrating the endpoint into the app.Debugging a third-party API integration
Teams can isolate whether a failure comes from headers, auth, payload formatting, or query construction.Reproducing a support issue
Support and QA can replay the same request conditions and inspect what the service actually returns.Sharing reusable endpoint setups
Saved endpoint definitions make it easier to keep common request patterns ready for future testing.
5How to Use It
- 1Enter the endpoint URLAdd the API URL you want to test, including any base path needed for the request.
- 2Choose the HTTP methodSelect GET, POST, PUT, DELETE, or another supported method based on the endpoint behavior.
- 3Add headers, params, and bodyConfigure the request details such as auth headers, query parameters, and JSON body content.
- 4Send the requestRun the request through the tool and wait for the response details to appear.
- 5Inspect and iterateReview the response, make adjustments, and resend until the behavior matches expectations.
Developer Note
Furkan Beydemir - Frontend Developer
I use API clients mostly for fast iteration, not ceremony. This tool is built for those moments when you just need to send a request, inspect the result, and adjust something immediately.
Examples
GET users endpoint
Input: GET https://jsonplaceholder.typicode.com/users
Output: A successful JSON response with a user list and visible status metadata.
POST request with JSON body
Input: POST request with `Content-Type: application/json` and a sample payload
Output: A request-response cycle suitable for checking body parsing and response behavior.
Auth header debugging
Input: A saved endpoint with custom headers and query parameters
Output: A reproducible request configuration useful for integration troubleshooting.
Troubleshooting
The request fails even though the endpoint is correct
Cause: Headers, auth tokens, body shape, or query parameters may still be incorrect for the endpoint's expected contract.
Fix: Compare the request carefully against the API documentation and test each input piece step by step.
The response is not what I expected
Cause: The endpoint may be behaving correctly while the request assumptions are wrong, or the environment may differ from the intended one.
Fix: Check the method, URL, params, body, and environment target, then compare the response with the documented behavior.
A saved request no longer works later
Cause: APIs evolve, auth tokens expire, and environments change over time.
Fix: Refresh the saved request details and revalidate any headers, credentials, or request bodies that may have changed.
FAQ
What kinds of API requests can I send with this tool?
The tool supports common HTTP methods including GET, POST, PUT, DELETE, PATCH, HEAD, and OPTIONS. You can also attach headers, query parameters, and request bodies, which covers a large portion of practical REST-style API testing workflows.
Why use an API test client instead of curl?
Command-line tools are powerful, but a browser-based client is often faster for exploratory testing, comparing headers, editing payloads, and reviewing responses visually. It is especially useful when you want a more interactive workflow or when non-terminal users need to test an endpoint.
Can I save endpoints for later?
Yes. The tool includes saved endpoint support and request history, which helps when you revisit the same APIs often or want to keep useful test setups ready for repeated debugging and validation work.
Does this help with debugging API errors?
Yes. It is useful for checking status codes, response payloads, headers, timing, and request construction. That makes it easier to isolate whether a bug comes from the endpoint, the request body, missing headers, auth issues, or query parameter handling.
Is this meant to replace a full API platform?
Not necessarily. It covers many day-to-day testing needs, especially for quick request-response work. Larger teams may still use broader platforms for collections, automation, team collaboration, and advanced scripting, but a focused browser client is extremely useful for fast checks.
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Blog Posts About This Tool
Learn when to use API Test, common workflows, and related best practices from our blog.
