YurlieUUID Generator
Generate cryptographically random UUID v4 or time-ordered UUID v7 in multiple formats.
UUID v4— randomly generated, 122 bits of cryptographic randomness. Best for most use cases where ordering doesn't matter.
UUID v4 vs UUID v7
| Property | UUID v4 | UUID v7 |
|---|---|---|
| Generation | Fully random | Time-ordered + random |
| Sorting | Random order | Sorts by creation time |
| Database index | Poor (random inserts) | Excellent (sequential) |
| Privacy | No timestamp info | Embeds millisecond timestamp |
| Best for | General purpose IDs | Database primary keys |
UUID formats
| Format | Example |
|---|---|
| Standard | 550e8400-e29b-41d4-a716-446655440000 |
| No hyphens | 550e8400e29b41d4a716446655440000 |
| Braces | {550e8400-e29b-41d4-a716-446655440000} |
| URN | urn:uuid:550e8400-e29b-41d4-a716-446655440000 |
Frequently Asked Questions
Are the generated UUIDs unique?
UUID v4 uses 122 bits of cryptographic randomness, giving a collision probability of approximately 1 in 5.3×10³⁶. In practice, UUIDs are considered globally unique.
What is the difference between UUID and GUID?
They are the same thing. GUID (Globally Unique Identifier) is Microsoft's name for UUID (Universally Unique Identifier). Both follow the same RFC 4122 standard.
Is this tool sending my UUIDs to a server?
No. UUIDs are generated entirely in your browser using crypto.getRandomValues(), a cryptographically secure random number generator built into modern browsers.