Network
API Tester
Postman style REST client
Guide & documentation
How to use API Tester
DevsWallet API Tester is an interactive HTTP client for checking REST endpoints without installing a desktop application. Build a request with its method, URL, query parameters, headers, authentication, and body, then inspect the status, response headers, payload, and timing in one workspace. It is useful for reproducing a backend bug, validating a webhook receiver, comparing staging with production, or turning an API specification into a concrete request. Requests can contain secrets, so use test credentials, prefer HTTPS, and remove tokens before sharing screenshots or exported examples.
API Tester runs in your browser on DevsWallet. Use the steps below for a first successful run, then open the full guide if you need deeper examples, FAQs, and troubleshooting.
Step by step
- Enter an HTTPS endpoint and select the exact HTTP method documented by the API.
- Add query parameters and headers deliberately; use the Authorization control for test credentials instead of embedding secrets in the URL.
- For POST, PUT, or PATCH requests, choose the body format expected by the server and validate JSON before sending.
- Send the request, then verify the status code, content type, response body, and elapsed time rather than treating any 2xx response as automatically correct.
- Copy a redacted request into the bug report, including expected behavior and the smallest payload that reproduces the issue.
Common use cases
- Reproducing an API failure reported by a frontend application.
- Checking CORS, authentication, pagination, and validation behavior during integration work.
- Comparing response contracts between local, staging, and production environments.
- Testing a small request manually before encoding it in an automated integration test.
Expert deep dive
Exercise REST endpoints with methods, headers, auth, and bodies, similar to Postman for quick checks. Save collections and environments for regression testing across staging and production.
Frequently asked questions
- Is API Tester a replacement for automated tests?
- No. It is best for exploration and reproducible debugging. Once a request is stable, add it to your project’s automated contract or integration test suite.
- Why does a request work here but fail in my browser app?
- Browser applications enforce CORS and may send different cookies or headers. Compare the complete request in browser developer tools and check the server’s Access-Control-Allow-* response headers.
- Can I send production API keys?
- Use short-lived test credentials whenever possible. Never place secrets in URLs, screenshots, shared collections, or support tickets, and revoke any key exposed accidentally.
- What should I record when reporting an API bug?
- Record method, redacted URL, relevant headers, minimal body, status code, response body, timestamp, and the expected result. This gives maintainers enough context without exposing credentials.
Related Network tools
Need a longer walkthrough?
Scroll up to run API Tester, or open the full API Tester guide for extended examples and FAQs.
More on our blog, about page, or contact us with feedback about API Tester.
Full guide
API Tester: Postman Style REST Client in the Browser
API Tester how to for api tester: open the tool, run a tiny sample, then save the result.