Random JSON Data Generator
Build a schema and generate random JSON test data — names, emails, UUIDs, dates and custom value lists.
Schema
How it works
Build a schema row by row — a field name plus a data type such as UUID, full name,
email, price, ISO date or a custom "One of" list — then choose how many records you
want and the generator writes ready-to-use mock JSON instantly. Pick an array, an
object with a data wrapper, or NDJSON for log and bulk-import formats,
and switch between pretty-printed and minified output. Enter a seed to get exactly
the same random JSON data every time, which is ideal for reproducible tests and
fixtures; leave it blank and every click of Regenerate gives fresh values. All the
random data is generated by JavaScript in your browser — no API calls, no sign-up,
no rate limits, and nothing you type ever leaves your device.
Frequently asked questions
How do I generate random JSON data online?
Add a row for every field you need, give it a name and pick a type such as UUID, full name, email, price, ISO date or a custom "One of" list. Set how many records you want and the JSON appears instantly below the schema — then copy it or download it as a .json file. Nothing is sent anywhere, so there is no sign-up and no row limit.
Is this random JSON data generator free and private?
Yes. The generator is completely free with no account, no ads and no API key. All the fake data is produced by JavaScript running in your own browser, so your schema, field names and generated records never touch a server — unlike most online mock data tools, which post your schema to their backend.
Can I get the same random JSON data every time?
Yes — type anything into the Seed box (for example "42") and the generator becomes deterministic: the same seed always produces exactly the same JSON, which is perfect for reproducible test fixtures and snapshot tests. Leave the seed blank and every click of Regenerate gives fresh values. You can also switch the structure to an array, an object with a "data" key, or NDJSON for bulk imports and log files.