Mock Data Generator (JSON, CSV, SQL)

Mock Data Generator

Build a schema, see the preview instantly and download thousands of rows of fake data as JSON, CSV, SQL, XML or NDJSON. No fixed row cap and nothing sent to servers.

See details

Runs in your browser
No signup
Embeddable
Productivity
Updated on October 18, 2026

About the mock data generator

Realistic, reproducible test data, including Brazilian and US documents.

Each column in the schema has a type (there are 98, in 11 groups: person, Brazilian documents, US and international documents, address, internet, finance, commerce, dates, numbers and logic, text and identifiers) and its own options, such as date range, distribution, null percentage and unique values. Documents reuse the site's own generators: CPF, CNPJ (including the alphanumeric one), CNH, PIS and voter ID close their check digits; the SSN follows the Social Security Administration exclusions (area 000, 666 and 900 to 999, group 00 and serial 0000); test cards pass the Luhn algorithm and IBANs pass the ISO 13616 mod 97 check. Emails use example.com, example.org and example.net, reserved by RFC 2606 for use as examples, and IPv6 addresses fall in the 2001:db8::/32 block (RFC 3849), so none of it points to real mailboxes or servers. The same seed with the same schema always produces the same data, and every field has its own random stream: adding a column does not change the others. Name, email, username, height and weight on the same row come from the same person, and city, state and ZIP (or CEP) come from the same address. With several tables, a foreign key draws values from another table, which is generated first, and the SQL comes out with CREATE TABLE and FOREIGN KEY. Generation runs in a browser Web Worker in blocks of 2,000 rows, so the page does not freeze; in Chromium browsers, files of 100,000 rows or more can be written straight to disk without building everything in memory. The practical limit is your device's memory and disk space, not a fixed row count: tools that generate on a server usually restrict the free plan (the Mockaroo page lists 1,000 rows per generation).

How to use

Pick a schema, tweak the fields and download.

Pick a ready-made schema (users, orders with three linked tables, products, Brazilian customers with CPF, US customers with SSN, logs or transactions) or start from what is on screen. Set the data language (PT-BR or EN-US) and the seed.
Edit the columns: name, type, null percentage and each type's options, such as range, distribution, weighted list, text templates that join other fields and expressions like quantity times price. The preview shows the first 20 rows and a sample of the output in the chosen format.
Choose the format (JSON, NDJSON, CSV, TSV, SQL, XML or TypeScript types), adjust the options and download the file. With several tables, download them one by one or all in a .zip. Save the schema as JSON or copy the link to repeat the run later.

Embed

Use this tool on your site

Paste the code into your HTML and the tool shows up on your page, without J-Kit's navigation and ads. It still runs in the browser of whoever visits your site.

https://jkit.tools/embed/en-US/mock-data-generatorOpen

Size

Height (px)

Width

html

<iframe
  src="https://jkit.tools/embed/en-US/mock-data-generator"
  width="100%"
  height="600"
  style="border:0"
  loading="lazy"
  title="Mock Data Generator (JSON, CSV, SQL)"
></iframe>

References

Sources and references for this tool

These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.

FAQ

Frequently asked questions

Is there a row limit?

There is no fixed row limit beyond a safety ceiling of 100 million per table, which only guards against typos. The real limit is your device's memory and disk: data is generated in blocks of 2,000 rows and the browser builds the file piece by piece. In Chromium browsers, from 100,000 rows the tool asks for a location to write straight to disk, without gathering the whole file in memory. The estimated file size appears below the preview, computed from the sample, and you can cancel a long run at any time.

Does my data leave my browser?

Are the generated CPFs, SSNs and cards real?

How do I get exactly the same data again?

How do multiple tables and foreign keys work?

How do I create calculated fields, like an order total?

How is the SQL generated?

Does the CSV open well in Excel?

What happens with unique values and nulls?

How do I save the schema and share it with my team?

Productivity

Mock Data Generator (JSON, CSV, SQL)

Mock Data Generator

Realistic, reproducible test data, including Brazilian and US documents.

Pick a schema, tweak the fields and download.

Use this tool on your site

Sources and references for this tool

Frequently asked questions

Related tools

Mock Data Generator (JSON, CSV, SQL)

Output

Mock Data Generator

Realistic, reproducible test data, including Brazilian and US documents.

Pick a schema, tweak the fields and download.

Use this tool on your site

Sources and references for this tool

Frequently asked questions

Related tools

Output

Mock Data Generator

Realistic, reproducible test data, including Brazilian and US documents.

Pick a schema, tweak the fields and download.

Use this tool on your site

Sources and references for this tool

Frequently asked questions

Where to go next

Related tools

Output

Mock Data Generator

Realistic, reproducible test data, including Brazilian and US documents.

Pick a schema, tweak the fields and download.

Use this tool on your site

Sources and references for this tool

Frequently asked questions

Where to go next

Related tools

Output