UUID & ULID Generator
Free online UUID generator. Generate UUID v4, UUID v1, ULID, NanoID in bulk. Validate and compare different ID formats.
| Format | Length | Sortable | Example |
|---|---|---|---|
| UUID v4 | 36 chars | No | 550e8400-e29b-41d4-a716-446655440000 |
| UUID v1 | 36 chars | Partially | 6ba7b810-9dad-11d1-80b4-00c04fd430c8 |
| ULID | 26 chars | Yes | 01ARZ3NDEKTSV4RRFFQ69G5FAV |
| NanoID | 21 chars* | No | V1StGXR8_Z5jdHi6B-myT |
| CUID | 25 chars | Yes | clh3j8qxj0000qzrmn831i7rn |
Generate unique identifiers in various formats including UUID v4, UUID v1, ULID, NanoID, and CUID. Perfect for database primary keys, API resources, and file naming.
All IDs are generated locally in your browser using cryptographically secure random values.
How to Use This Tool
- 1 Select the ID format you need (UUID v4, ULID, etc.)
- 2 Choose how many IDs to generate
- 3 Adjust format options if needed
- 4 Click Generate to create new IDs
- 5 Copy individual IDs or all at once
Use Cases
Database Keys
Generate unique primary keys for database records without collisions.
API Resources
Create unique identifiers for API endpoints and resources.
File Naming
Generate unique file names to prevent overwrites in storage.
Session Tokens
Create unique session identifiers for user authentication.
Frequently Asked Questions
What's the difference between UUID v1 and v4?
UUID v1 includes timestamp and MAC address (partially sortable), while v4 is completely random. v4 is more common for privacy and simplicity.
What is ULID?
ULID (Universally Unique Lexicographically Sortable Identifier) is a 26-character ID that's time-sortable. It's great for databases where you want chronological ordering.
Are these IDs truly unique?
UUID v4 has 122 random bits, making collisions astronomically unlikely. You'd need to generate billions of IDs per second for years to have a 50% chance of collision.
Which format should I use?
Use UUID v4 for general purposes, ULID if you need sortability, NanoID for shorter URLs, and CUID for distributed systems requiring uniqueness guarantees.
Can I use these as passwords?
While cryptographically random, UUIDs aren't designed for passwords. Use a dedicated password generator with proper entropy for security-critical applications.