API Mock Response Maker

Generate realistic mock API responses without spinning up a backend. Configure status codes, headers, delays, and JSON payloads, then copy ready-to-use response snippets for Postman, MSW, Express, or plain .http files.

Validate and format JSON payloads before shipping a mock.
Auto-add CORS headers and synthetic latency for front-end flows.
Export HTTP response blocks or code snippets in a single click.
Store reusable presets for success, error, and collection shapes.

Waiting for configuration...

Endpoint Setup

Describe the surface you want to simulate. Values update the response preview automatically.

HTTP Method Status Code Status Text Base URL Endpoint Path Simulated Delay (ms)

Automatically add permissive CORS headers

HTTP Response Preview

Copy directly into tools like VS Code REST client or hoppscotch.

Method: GET

Status: 200 OK

Full URL: https://api.example.com/v1/example

Response Body

Paste or author the payload you expect the client to handle. Use the presets to jump-start common scenarios.

Headers

Add or override headers as needed. Empty fields are ignored in the preview.

Mock Snippet

Choose a target and grab ready-to-paste mocking code.

Snippet Style

Usage Tips

Need XML or plain text? Change the Content-Type header and paste raw payloads—validation gracefully falls back to plain text.
Use the simulated delay to expose loading states or race conditions during demos.
Save multiple mocks by downloading .http files and checking them into your repository alongside integration tests.
Combine the snippet output with tools like MSW, Mirage, Playwright, or Newman to keep client flows hermetic.