Mock Data Generator
Generate realistic fake data for testing. Export as JSON, CSV, SQL INSERT, or TypeScript.
About This Tool
The Mock Data Generator creates realistic test data directly in your browser. Define a custom schema by picking field names and types — first names, emails, phone numbers, UUIDs, dates, and many more — then generate up to 1,000 rows at once. All data is produced using a lightweight built-in faker engine with no external dependencies.
Output is available in four formats: JSON (array of objects), CSV (with header row), SQL INSERT (with customizable table name), and TypeScript (typed array with auto-generated interface). Each format is ready to paste into your project, test suite, or database seed script.
A seed value enables reproducible output — the same seed and schema always produce identical data. This is especially useful for snapshot tests and deterministic CI pipelines. For generating unique identifiers, see the <Link href={getLocalePath(locale, "/tools/uuid-generator")} className="text-primary underline underline-offset-2"
UUID Generator . Need placeholder paragraphs instead of structured data? Try the <Link href={getLocalePath(locale, "/tools/lorem-ipsum-generator")} className="text-primary underline underline-offset-2"
Lorem Ipsum Generator .
All processing happens client-side — your schema definitions and generated data never leave your device. The tool supports English and Japanese locales for name and address fields, making it suitable for internationalized applications. Format your JSON output with the <Link href={getLocalePath(locale, "/tools/json-formatter")} className="text-primary underline underline-offset-2"
JSON Formatter for easy inspection.
How to Use
- Click Add Field to define your schema. Enter a field name and choose a data type from the dropdown.
- Set the row count using the slider or input (1 – 1,000).
- Optionally enter a seed value for reproducible output.
- Select a locale (English or Japanese) for locale-sensitive fields.
- Click Generate or press Ctrl+Enter to produce the data.
- Switch between output tabs (JSON, CSV, SQL, TypeScript) and click Copy or Download to export.
FAQ
Is my data safe?
Yes. All data generation happens entirely in your browser using JavaScript. No data is sent to any server — not even the schema you define.
Is the generated data truly random?
The data is pseudo-random. If you provide a seed value, the same seed always produces the same output, which is useful for reproducible test fixtures. Without a seed, the output changes on every generation.
What data types are supported?
The tool supports over 20 types including firstName, lastName, fullName, email, phone, address, city, country, zipCode, UUID, date, URL, IPv4, IPv6, hex color, company name, job title, boolean, integer, float, and paragraph.
What output formats are available?
You can export as JSON (array of objects), CSV (comma-separated with header row), SQL INSERT statements (with customizable table name), or TypeScript (typed array with interface).
How many rows can I generate?
You can generate between 1 and 1,000 rows at a time. Generation is instant for most schemas. Very complex schemas with many fields may take slightly longer at the upper limit.
Does it support multiple languages?
Yes. The tool includes name and address data pools for English (en) and Japanese (ja) locales. The locale toggle switches the data source for locale-sensitive fields like names, cities, and addresses.
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