Tools / Category
API Testing tools
Payloads, cURL, assertions and HTTP references.
- API Payload Generator Generate a valid API request body plus labelled negative payloads (missing fields, wrong types, boundaries, bad formats) from a JSON Schema or sample. Free.
- Sample JSON Payload Library Searchable library of realistic JSON payloads for API testing: auth, pagination, problem+json errors, orders, payments, webhooks and GraphQL. Copy or download.
- HTTP Status Code Reference HTTP status codes for testers: meaning, when an API should return each 1xx-5xx code, what to verify and common bugs like 200 with an error body. Searchable.
- HTTP Headers Reference HTTP headers reference for API testers: content negotiation, caching, ETags, CORS, security headers, cookies, rate limits and tracing, with what to test.
- cURL Command Generator Build curl commands from a form or parse pasted curl, then convert to fetch, Playwright, Python requests and REST Assured. Bash, cmd and PowerShell quoting.
- cURL to Code Converter Paste a curl command and get a Playwright API test, a REST Assured given/when/then chain, Python requests or fetch. Handles “Copy as cURL” and Windows quoting.
- API Response Validator Paste an API response and run checks like a test runner: JSONPath exists, equals, type, regex and length, plus status and header assertions. Free, in-browser.
- API Assertion Builder Paste a JSON response, tick fields and get assertion code for Playwright, Postman pm.test, REST Assured or Cypress, with exact-value or type-only checks.
- REST API Test Case Templates Describe a REST endpoint and get a test case checklist: positive, negative, auth, validation, boundary, pagination, idempotency, rate limits. Markdown or CSV.
- Auth Header Generator Generate Authorization headers for Basic (UTF-8 safe), Bearer and API keys, with cURL and Playwright extraHTTPHeaders snippets and an OAuth token request.