Antimass Labs Tutorials
Guides for every tool in the Antimass Labs suite. Learn how to generate mock data, spin up instant APIs, seed test databases, and more — with new tools and tutorials added regularly.
How to Generate Swedish Personnummer Test Data in Your Browser
Generate valid Swedish personal identity numbers (personnummer) for testing. Learn the YYYYMMDD-XXXX format, Luhn checksum validation, and how to create realistic Swedish test data locally with zero server dependencies.
How to Turn JSON into a Mock CRUD API in 60 Seconds
Convert any JSON payload into a fully functional REST API with GET, POST, PUT, and DELETE endpoints instantly. No sign-up, no backend code, no deployment. Self-cleaning endpoints powered by edge infrastructure.
How to Seed Postgres Test Data Deterministically
Generate deterministic INSERT statements for PostgreSQL test databases. Learn schema-first seeding with foreign key resolution, realistic data types, and reproducible test fixtures using the Antimass Labs SQL Seeder.
How to Generate QA Edge Cases with Chaos Mode
Stress-test your application with boundary values, Unicode injection, null fields, and extreme data lengths. Learn how Chaos Mode in the Antimass Labs Data Generator creates adversarial test data to find bugs before your users do.
Mockaroo Alternative: Privacy-First Local Test Data Generation
Compare Antimass Labs vs Mockaroo for mock data generation. Generate realistic test data entirely in your browser — no accounts, no API limits, no data uploaded to third-party servers. A free, privacy-first Mockaroo alternative.
JSONPlaceholder Alternative: Writable Temporary REST Endpoints
Looking for a JSONPlaceholder alternative with writable endpoints? Antimass Labs Stateful API lets you POST, PUT, and DELETE — not just GET. Create disposable CRUD APIs with your own data, no backend required.