HTTP Mock Response Builder

An HTTP mock response simulates a real API response for testing or development purposes without hitting an actual server. It lets you define the status code, headers, and body so your frontend code or tests can run against predictable, controlled data — no backend dependency needed.

A fetch mock replaces the global fetch function in a test file with a jest.fn() that returns a pre-configured Response. It's simple and works for unit tests. An MSW (Mock Service Worker) handler intercepts real network requests at the service worker or Node.js level, making it ideal for integration tests with React Testing Library or Playwright — your app code stays unchanged.

The generated curl command is useful for documenting expected API behavior in runbooks or READMEs, testing how your frontend handles specific response shapes via a local proxy, and sharing a reproducible example with teammates. For actual test mocking, prefer the fetch mock or MSW handler.

Select status 204 from the presets and set the body format to 'empty'. A 204 response should have no body by spec. The generated fetch mock will set body to null and the MSW handler will return new HttpResponse(null, { status: 204 }).

Use the Custom Headers section to add headers like Authorization: Bearer fake-token, X-API-Key: test-key, or any other header your app reads. These headers are included in the curl command and the fetch/MSW mocks.

Yes. Select 'text', 'html', or 'xml' from the Body Format options and write your body content. The Content-Type header is automatically set to match — text/plain, text/html, or application/xml respectively.