Free Online Mock API & REST Generator
Generate dynamic, realistic dummy data using Faker-style mustache syntax (`{name.first}`). Simulate harsh network latency, force HTTP error codes, and copy the client-side Fetch/Axios implementations to test your UI without waiting for backend teams.
This tool operates entirely within your browser. You do not need to deal with CORS origin flags or rely on external API uptime. Generate your schema, configure your network conditions, and copy the `fetch()` snippet directly into your frontend to bypass remote hosting entirely.
Pre-Built Scenarios
My Templates
[
{
"id": 1,
"fullName": "Carol Alice",
"email": "[email protected]",
"avatar": "https://i.pravatar.cc/150?u=3756",
"role": "role_1",
"active": false,
"createdAt": "2025-12-28"
},
{
"id": 2,
"fullName": "Bob Iris",
"email": "[email protected]",
"avatar": "https://i.pravatar.cc/150?u=4996",
"role": "role_2",
"active": true,
"createdAt": "2025-08-06"
},
{
"id": 3,
"fullName": "Frank Alice",
"email": "[email protected]",
"avatar": "https://i.pravatar.cc/150?u=9245",
"role": "role_3",
"active": true,
"createdAt": "2025-11-22"
},
{
"id": 4,
"fullName": "Bob Frank",
"email": "[email protected]",
"avatar": "https://i.pravatar.cc/150?u=8215",
"role": "role_4",
"active": false,
"createdAt": "2025-08-17"
},
{
"id": 5,
"fullName": "Eve Alice",
"email": "[email protected]",
"avatar": "https://i.pravatar.cc/150?u=8299",
"role": "role_5",
"active": true,
"createdAt": "2025-10-08"
}
]About the API Response Mockup Tool
Frontend development shouldn't be blocked waiting for a backend API. Mock API responses let you build and test UI components against realistic data immediately. This tool generates mock JSON (or XML) responses from Mustache templates with faker.js-style field names — configurable status codes, response counts, and locale-aware data.
What this tool generates
Template-Based Generation
Define your response shape with Mustache templates. Use {{name}}, {{email}}, {{uuid}}, {{date}} and 50+ field types.
Pre-built Scenarios
Ready-made templates for common API patterns: user list, product catalog, order history, error responses, and paginated results.
Status Code Simulation
Configure any HTTP status code to test how your frontend handles success, validation errors, auth failures, and server errors.
Code Snippets
Generates fetch, axios, and cURL snippets for the mock endpoint — copy directly into your frontend code or test suite.
Pipeline
- JSON Schema Generator — generate a schema from your mock response to validate real API responses.
- JSON to TypeScript — generate TypeScript types from your mock data shape.
- cURL to Code — convert the generated cURL snippet to your language of choice.
Frequently asked
- Is my data sent to a server?
- No. All mock data generation runs 100% in your browser. Your templates and generated data never leave your device.
- What is a mock API and why do I need one?
- A mock API simulates the responses of a real API without requiring a backend. It lets frontend developers build and test UI components before the real API is ready, and lets QA engineers test edge cases (empty states, errors, large datasets) that are hard to reproduce with real data.
- What template syntax does this tool use?
- Mustache-style templates with faker.js-compatible field names. Use {{name}}, {{email}}, {{uuid}}, {{date}}, {{number}}, {{boolean}}, and many more. Nested objects and arrays are supported.
- Can I simulate HTTP error responses?
- Yes. Configure the response status code (200, 201, 400, 401, 403, 404, 422, 500, etc.) and the tool generates the appropriate response envelope. Useful for testing error handling in your frontend code.
- Can I export mock data as XML?
- Yes. Switch to XML output mode to get the generated data as XML instead of JSON — useful for testing SOAP clients or XML-consuming systems.