UUID / ULID Generator
Generate unique identifiers instantly. UUID v4, v7, ULID, and NanoID — all locally in your browser.
8207f95b-7e20-4a25-80f2-71b69ed8e2ff
Options
e.g. f47ac10b-58cc-4372-a567-0e02b2c3d479
All IDs are generated entirely in your browser using crypto.randomUUID() and crypto.getRandomValues(). Nothing is ever transmitted or stored on our servers.
UUID vs ULID vs NanoID
Choosing the right identifier format depends on your use case. Here's a quick comparison:
| Feature | UUID v4 | UUID v7 | ULID | NanoID |
|---|---|---|---|---|
| Length | 36 chars | 36 chars | 26 chars | 21 chars |
| Sortable | No | Yes | Yes | No |
| Timestamp | No | Yes | Yes | No |
| Best for | General use | Database PKs | Distributed systems | Short URLs |
When to Use Each Format
- UUID v4 — The universal default. Supported natively by every database and language. Use when you just need a unique ID with no special requirements.
- UUID v7 — The modern choice for database primary keys. The embedded timestamp means sequential inserts are naturally ordered, reducing B-tree index fragmentation.
- ULID — Perfect for distributed systems where you need sortable IDs without coordination. The Crockford Base32 encoding is case-insensitive and avoids ambiguous characters.
- NanoID — Best when ID length matters. At 21 characters with a URL-safe alphabet, it's ideal for client-side IDs, URL slugs, and file names.