Free Online Mock API Generator

This tool turns a schema of field names and types into a downloadable JSON array that stands in for an API response during frontend work.

Your data is processed entirely in your browser and never sent to any server.

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Schema

Records:

JSON response

[
  {
    "id": "9e5ce83e-9dea-4df8-ae8e-edb83684c391",
    "name": "bravo"
  },
  {
    "id": "136be771-4a1f-43cf-9a2a-21b9f00bef56",
    "name": "hotel"
  },
  {
    "id": "c611b634-1d48-4f03-a3cf-d1da6e8feed5",
    "name": "delta"
  },
  {
    "id": "31ea2197-c17e-4204-9dd9-32c117d15f3c",
    "name": "echo"
  },
  {
    "id": "adc94545-91a7-48d3-ac84-d950474b59d9",
    "name": "hotel"
  }
]

How to Use This Tool

Add a row for each field, giving it a name and a type.
Use Add field and the remove button to shape the schema.
Set the number of records to generate.
Click Regenerate for a fresh set of values.
Copy or download the JSON array for your frontend mock.

What Is a Mock API Generator?

Frontend development often races ahead of the backend, so you need a realistic JSON response before the real endpoint exists. This generator builds one from a simple schema. Add rows of field name plus type — string, number, boolean, email, uuid, or date — choose how many records you want, and it emits a JSON array of objects matching that contract, formatted and ready to paste into a fixture or fetch mock.

Values are generated locally with crypto.getRandomValues, and UUIDs use crypto.randomUUID where available, so each field is filled with type-appropriate placeholder data: numbers are numbers, booleans are true or false, dates are ISO calendar strings, emails follow a name@example.com shape. Because it is regenerated on demand, you can produce as many distinct records as a test needs without writing them by hand.

This is a static-JSON generator, not a live mock server — you copy or download the result and serve it from a local file, a fixtures folder, or a stubbed fetch. Pair it with the fake-data generator when you want tabular CSV instead. Nothing leaves your browser, so the mock data is entirely yours.

Frequently Asked Questions

How do I define the response?

Add rows of field name plus type (string, number, boolean, email, uuid, date) and set a record count; the tool builds matching JSON objects.

Is it a live mock server?

No. It generates static JSON you copy or download. Serve it from a local file or paste it into a fixture for your frontend tests.

Where does the data come from?

Values are generated locally with crypto.getRandomValues, so nothing leaves your browser and you can regenerate fresh data anytime.

Published by the WeGotEveryTool team. We build and test every tool in-house and update pages when the underlying spec, formula, or recommendation changes.

Reviewed: May 2026. Disclaimer: this tool is provided as-is for general informational use. For decisions with material consequences (medical, legal, financial, security) verify results against a qualified professional source.

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