UUID Generator — Generate Random v4 UUIDs

#What this tool does

Generate v4 UUIDs using crypto.randomUUID() — the Web Crypto API backed by a cryptographically secure random number generator. Generate up to 50 at once, copy individually or all at once.

#UUID versions

v4 (random) — 122 random bits. The most widely used version. Collision probability is vanishingly small — 2.7 quintillion UUIDs for a 50% chance of one duplicate.

v7 (timestamp + random) — embeds a Unix millisecond timestamp, making UUIDs sortable by creation time. Better for database primary keys because B-tree indexes maintain insertion order.

v1 (timestamp + MAC) — reveals when and where it was generated. Avoid for most modern use cases.

For new database projects, prefer v7 for primary keys and v4 for security-sensitive tokens (session IDs, API keys).

#When to use UUIDs

• Database primary keys — no conflicts across distributed shards
• API resource identifiers — don't leak record count like auto-increment IDs
• Idempotency keys — prevent duplicate API request processing
• Correlation IDs — trace requests across microservices

#Open source

This tool is powered by @azin-tech/mini-tools, an open-source developer toolkit. View source on GitHub.