How to use the API Test Case Generator
- 1. Describe the endpointMethod, path, authentication, success status, and a sample JSON body or query parameters.
- 2. Mark required fieldsList required fields and the maximum text length.
- 3. GenerateDownload a CSV test case table or a Postman collection with a status check for each case.
How the cases are chosen
The generator reads your sample body and works out each field's type from its value and name: text, number, boolean, list, email, Indian mobile number, date, URL or PIN code. For every field it adds the checks testers rely on: missing and null values for required fields, the wrong type, empty and space-only text, length just at and just over the limit, Hindi letters and apostrophes, script and SQL-injection text, impossible dates, short phone numbers, zero, negative and very large numbers. Around those it adds request-level cases: no credentials, bad credentials, no permission, malformed JSON, wrong content type, unknown fields, duplicate creates, oversized payloads, rate limits, method not allowed and HTTPS. Everything runs in your browser; nothing you type or choose is uploaded.
The Postman export gives each case its own request with the changed body or headers and a test that checks the expected status codes.
Worked example
The default is POST /api/v1/students with a bearer token, success status 201 and a six-field body (name, email, phone, course, fee and isActive), four of them required. The tool generates 60 test cases, 28 of them high priority: 24 validation, 15 boundary, 6 negative, 6 security, 3 positive, 3 authentication and one each for authorisation, rate limiting and concurrent requests. Exported to Postman, that's 60 ready-to-run requests.
Using the cases
- Expected codes follow common REST conventions (400 or 422 for validation, 401, 403, 404, 409, 413, 415, 429); your API specification has the final say.
- Run security cases only against systems you're allowed to test.
- Add business rules the tool can't know, such as fee limits or which courses exist.
Frequently asked questions
Does it call my API?
No. It only writes the test cases; you run them in Postman or your own test framework.
Can I use it for GET requests?
Yes. Choose GET and list the query parameters; it adds paging, limits, sorting and search cases.
Is the API test case generator free?
Yes. You can open the API test case generator and fill in every option without signing up. When you generate test cases for the first time, we ask once for your name and WhatsApp number; after that it, and every other Uncodemy tool, opens straight away.