Free realistic test data generator — CSV, JSON & SQL
Design a schema and export up to 100,000 realistic rows. Free, private and reproducible — directly in your browser, with 60+ field types and CSV, JSON, SQL, XML and NDJSON export. No signup; your data never leaves your machine.
1 · Design your schema
2 · Generate & export
← scroll sideways for more columns →
Why Fun Data Playground?
60+ realistic field types
Names, emails, phone numbers, street addresses, companies, products, prices, IPs, UUIDs, dates and more — organized into groups. See the full field type reference.
Six export formats
CSV and TSV for spreadsheets, JSON and NDJSON for APIs and pipelines, SQL inserts (with CREATE TABLE) for databases, and XML for legacy systems.
Reproducible with a seed
Type any seed string and every run produces byte-identical data. Share the seed with your team or pin it in CI for stable, repeatable test fixtures.
Private by construction
Generation is 100% client-side JavaScript. Your schema lives in your browser's localStorage and generated rows never touch a server.
Nullable columns & patterns
Give any field a blank percentage to simulate missing data, or build custom formats with pattern fields (# digit, ? A–Z, ~ a–z) and custom value lists.
Templates to start fast
One click loads ready-made schemas: users, e-commerce orders, employees, IoT sensor readings or bank transactions — then tweak from there.
Built for real test workflows
Use practical patterns for database seeding, mock APIs, QA automation and spreadsheet samples.
Documented and test-safe
Reserved domains and network ranges keep synthetic values away from real recipients. Read the generation, privacy and safety methodology.
How it works
- Design a schema. Add fields, name them, pick a type and fine-tune options like min/max, date ranges or custom value lists.
- Choose rows, format and seed. Anything from 1 to 100,000 rows; leave the seed empty for fresh random data or set one for reproducible output.
- Download or copy. Preview updates live as you edit. Export the full dataset as a file or copy it straight to the clipboard — or share your whole schema as a link.
Need a mock backend to serve this data? That's what our sibling Fun API Playground is for. Practicing UI automation instead? Head to Fun UI Playground. Or choose a complete workflow from our synthetic test-data use cases.
FAQ
Is Fun Data Playground free?
Yes — completely free, no signup, no rate limits. Generation runs in your browser, so there's no server quota to hit.
Where does my data go?
Nowhere. The generator is 100% client-side. Your schema is saved to your own browser's localStorage and generated rows never leave your machine.
Can I reproduce the exact same dataset twice?
Yes. Enter any string in the Seed field — every run with the same seed and schema produces byte-identical output. Great for repeatable fixtures in CI.
Which export formats are supported?
CSV, TSV, JSON (array), NDJSON (one object per line), SQL INSERT statements with optional CREATE TABLE, and XML.
How many rows can I generate?
Up to 100,000 rows per download. Because everything runs locally, large exports depend only on your machine — there is no server-side cap below that.
Are the credit card numbers and IBANs real?
No. Card numbers are official payment-gateway test PANs, and IBANs are country-length-shaped but fake — they're for form validation and UI testing only.