Online Tool Store
Mock API Response Builder
Build a mock JSON API response — array, object, or paginated — from a simple field list with typed fake values. Runs entirely in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
Supported types: string, number, boolean, email, date, uuid.
How it works
- Define fields as `name:type`, one per line.
- Pick a status code, item count, and response shape.
- Copy the generated JSON into your mock server or test fixture.
FAQ
What field types are supported?
string, number, boolean, email, date, and uuid — enough to mock most typical API response shapes without needing real data.
What response shapes can I build?
An array of objects (a typical list endpoint), a single object (a detail endpoint), or a paginated shape with data, page, and total fields (a common REST list-with-pagination pattern).
Can I use this to actually mock an API endpoint?
This tool generates the JSON payload only — pair it with your own mock server, a browser extension like a request interceptor, or your test framework's fixture files to actually serve the response.
Is any data sent to a server?
No — every value is generated locally in your browser. Nothing is uploaded.
How we compare
| Feature | Online Tool Store | Faker.js in a script | Hand-written JSON fixture |
|---|---|---|---|
| No install or code editor | ✓ | Requires Node.js + a package | ✓ |
| Regenerate values with one click | ✓ | ✓ | Manual, slow, and error-prone |
For a quick fixture while building a UI before the real API exists, this beats writing a one-off script for a single mock payload.