Free Mock Data Generator

Browser-native localized CSV & JSON sequence generation. Generate highly realistic, region-specific mock data mathematically mapped to your chosen locale. Fully supports specialized regional formatting—like Swedish personnummer, US zip codes, German addresses, and Brazilian CPFs—securely on your machine with zero server bloat.

Data Generator

Browser-based CSV Test Data Generator. Create realistic, localized relational data securely on your machine.

Chaos Mode (Edge-Case Injection): Stop testing only the 'happy path'. Enabling Chaos Mode intentionally corrupts 10% of your dataset with known software-breaking edge cases, including:
  • Zalgo / Unicode text to test UI overflows.
  • SQL Injection strings (e.g., ' OR 1=1 --) to test sanitization.
  • Null bytes, 150+ character strings, and invalid date formats (Feb 29th on non-leap years).
  • Empty mandatory fields and Emoji-heavy strings.
Reveal UI crashes and unhandled backend exceptions before your users do.

Dynamic Attributes ⚡

You can now select exactly which columns to include in your CSV payload.

Data generation is intelligently correlated. For example, the chosen Email will probabilistically match the generated First Name and Last Name for that single row!

How it works ✨

Your data is generated entirely in the browser using @faker-js/faker. No data is sent to our servers, ensuring complete privacy.

We prepend a UTF-8 BOM and construct a JavaScript Blob from the elements to securely trigger an automatic, multi-lingual Excel-safe CSV download.

Related Tutorials

How to Generate Swedish Personnummer Test Data in Your Browser8 min read · 2026-04-15How to Generate QA Edge Cases with Chaos Mode7 min read · 2026-04-12Mockaroo Alternative: Privacy-First Local Test Data Generation6 min read · 2026-04-11

Frequently Asked Questions

No. The data generator is completely browser-native. We use deterministic algorithms running securely inside your local machine to generate thousands of records instantly without ever phoning home.
We map directly to region-specific rules. For example, our Swedish Personnummer generation mathematically validates the checksum, and our Indian vehicle plates follow regional RTO formats. It's not just random string manipulation.
Yes, you can export directly to CSV or JSON formats. If you need raw SQL insert statements, we recommend using our SQL Seeder tool instead.