Test data generator with valid checksums
Design a schema and download thousands of realistic fake rows as CSV, JSON or SQL. Valid IBANs and Luhn card numbers. Free, no account, runs entirely in your browser.
Why MockStack
Add columns, choose from 20+ realistic types, set ranges and locales.
IBAN mod-97, card Luhn and SIRET check digits are correct — they pass validation.
Export CSV, JSON or SQL INSERTs. Up to 50,000 rows, generated locally.
Free during beta
The generator is completely free right now. These paid tiers are a concept — payment is not active yet. Tell us which would be useful (an API? saved schemas?) and we'll invite you first.
- Up to 50k rows / run
- CSV · JSON · SQL
- Valid IBAN / Luhn / SIRET
- No account
- Everything in Free
- Save & share schemas
- Seeded (repeatable) data
- Relational / linked tables
- Everything in Pro
- REST API + CLI
- Higher row limits
- More locales & types
FAQ
Is MockStack free?
Yes. Generating and downloading test data is completely free during beta, with no account.
Do you store my schema or data?
No. Everything runs in your browser — nothing is uploaded to a server.
Are the IBANs and card numbers valid?
They carry valid checksums (IBAN mod-97, card Luhn, SIRET Luhn) so they pass format validation, but they are entirely fake and cannot be used for real transactions.
What formats can I export?
CSV, JSON and ready-to-run SQL INSERT statements. Up to 50,000 rows per run.
Why not just ask ChatGPT?
LLMs truncate long outputs, repeat rows, and emit IBANs/cards that fail checksum validation. MockStack outputs thousands of valid rows as a real downloadable file.