JSON Mock Data Generator

What is Mock Data?

The JSON Mock Data Generator creates realistic fake data for frontend prototyping, test fixtures, and demos. Define field names and types, pick a row count, and generate instantly — all offline, no server calls.

How it works

You define a list of fields with types (name, email, date, integer, address, etc.), and we generate N rows of realistic data using bundled generators. A seeded random ensures you get the same output for the same seed + field configuration.

1. Define your fields. Add fields with keys like 'name', 'email', 'age'. Pick the type from the dropdown — Name, Email, Date, UUID, Address object, and more.
2. Set row count and seed. Choose how many rows to generate. Change the seed to get different random data, or keep it fixed for reproducible output.
3. Copy or download. Copy the generated JSON array to clipboard or download as mock-data.json.

Examples

5 user records

Fields: id (ID), name (Name), email (Email), age (Age), city (City) produce 5 realistic user objects.

Custom enum field

Define a 'role' field with type 'Custom enum' and values 'admin,editor,viewer' to get randomly assigned roles.

Common mistakes

Too many rows for preview

Generating 10,000+ rows works but produces a large JSON string. Use Download instead of Copy for large datasets.

Seed not changing

The seed produces deterministic output. Change the seed value (or click Re-generate) every time you want different data.

Alternatives

JSON Schema Generator

Generate a schema from your existing data instead of creating data from a template.

CSV to JSON

If you have existing spreadsheet data, convert it to JSON instead of generating fake data.

Frequently asked questions