The UUID & ULID Generator creates universally unique identifiers for developers, database administrators and QA engineers. UUIDs are 128-bit values used as primary keys, correlation IDs and idempotency tokens because they can be generated independently without coordination and never collide in practice. This tool supports three formats: UUID v4 (fully random), UUID v7 (time-ordered, ideal for database indexes because it sorts chronologically) and ULID (a compact, URL-friendly, lexicographically sortable identifier). Everything is generated locally in your browser using the cryptographically secure Web Crypto API, so the values are safe to use and never leave your device.
How to Use the UUID Generator
- Choose the identifier type — UUID v4, UUID v7 or ULID — using the buttons at the top.
- Set how many you need (from 1 to 1000) and toggle formatting options such as hyphens and uppercase.
- Click Generate, then copy any single value or use Copy all to grab the whole batch for your seeds or tests.
Benefits and Use Cases
- Perfect for seeding databases, creating test fixtures and generating correlation IDs for distributed systems and logs.
- UUID v7 and ULID are time-ordered, reducing index fragmentation compared to random v4 keys in high-write databases.
- Runs entirely client-side with a secure random source, so generated identifiers are never transmitted or stored anywhere.