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Mock Data Generator — JSON, CSV, SQL & More

Generate realistic fake test data in 14 formats from 100+ field types, with reproducible seeds.

To generate mock data, pick a ready-made schema such as users, orders or products — or define your own columns from over 100 field types — then choose how many rows and which format. Output is available as JSON, CSV, SQL, XML, YAML, TypeScript and more, generated entirely in your browser.

Runs in your browser
Field types
97 across identity, contact, location, commerce, finance, dates, text and tech
Output formats
14 — JSON, NDJSON, CSV, TSV, XML, YAML, SQL, Markdown, HTML, TypeScript, JavaScript and Python
Maximum rows
5,000 per run
Reproducible
Seeded — the same seed always returns the same dataset
Privacy
Runs entirely in your browser — nothing is uploaded
Cost
Free, unlimited, no sign-up

Frequently asked questions

Is the generated data reproducible?

Yes. Every run is driven by a seed, so the same seed and settings always produce identical rows. Because the seed is part of the shareable link, a colleague opening your link sees exactly the same dataset.

Are the rows internally consistent?

Yes. Each record is built as one coherent person: the email matches the name, the postcode matches the country, and an "updated" date is never earlier than the matching "created" date.

Can I use this data in production?

No. It is synthetic test data. Card numbers and IBANs are structurally valid but deliberately non-functional, and names and addresses are randomly assembled rather than real.

How many rows can I generate?

Up to 5,000 per run. Generation happens in your browser, so the practical limit is your device memory rather than a server quota.

How to use the mock data generator

  1. 1Choose the data shape.
  2. 2Add each custom fields as a key and value pair.
  3. 3Set the number of rows.
  4. 4Choose the output format.
  5. 5Choose the locale.
  6. 6Enter or paste your table / root name.
  7. 7Enter or paste your seed.
  8. 8Set the empty / null values.
  9. 9Set the first sequential id.
  10. 10Enter or paste your wrap array in a key.
  11. 11The result appears immediately — copy or download it.

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Put the working mock data generator on your own site. It runs in your visitors' browsers exactly as it does here — free, no account, nothing uploaded.

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