Features
Generate UUID v1, v4, and v7
Generate ULID identifiers
Bulk generation of multiple IDs
Decode UUIDs to inspect version and variant
Copy with one click
Common Use Cases
- Generating primary keys for databases
- Creating unique identifiers for distributed systems
- Testing with random but valid UUIDs
Frequently Asked Questions
What is the difference between UUID v4 and v7?
UUID v4 is fully random. UUID v7 embeds a timestamp, making it sortable by creation time—ideal for database primary keys as it improves index performance.
What is a ULID?
ULID (Universally Unique Lexicographically Sortable Identifier) is a 26-character, timestamp-first identifier. It is sortable, URL-safe, and more compact than UUID.
Which should I use for database primary keys?
UUID v7 or ULID are best for database primary keys because their time-ordered nature improves B-tree index performance compared to random UUID v4.