UUID v7 Generator
Generate version 7 UUIDs with timestamp and randomness. Combines Unix timestamp with cryptographic randomness.
Configuration
Generated UUIDs
Generate UUID version 7
Format
UUID v7 is a time-based UUID with monotonic ordering:
xxxxxxxx-xxxx-7xxx-[89ab]xxx-xxxxxxxxxxxx
The 7 in the third group indicates version 7.
Structure
- Timestamp: 48 bits, Unix timestamp in milliseconds
- Random bits: 74 bits of cryptographically secure random numbers
- Version: 4 bits set to 0111 (version 7)
- Variant: 2 bits set to 10 (RFC 4122 variant)
Worked example
A typical UUID v7:
018f0e3a-5b3c-7abc-9def-0123456789ab
018f0e3a-5b3c-7= timestamp + version (v7)abc-9def= random0123456789ab= random
The timestamp is in milliseconds since 1 January 1970 (Unix epoch).
How to use
- Click "Generate" to create a new UUID v7
- Copy the result
- Repeat for multiple UUIDs
Monotonic ordering
UUID v7 is designed to be:
- Time-ordered: Later UUIDs sort after earlier ones
- Monotonically increasing: Within a single generator, UUIDs never "go backward"
- Database-friendly: Good for B-tree index ordering
Advantages
- Chronologically sortable: UUIDs sort by generation time
- Truly random: 74 random bits for uniqueness
- Cryptographically secure: Hard to guess
- Database efficient: Good for indexed columns
- Avoids v1 privacy issues: No MAC address included
Disadvantages
- Newer standard: Less widely supported than v1-v4
- Larger: 128 bits like all UUIDs
- Not universally adopted: Some systems may not support it
Comparison with v1
| Feature | UUID v1 | UUID v7 | |---------|---------|---------| | Timestamp | 60 bits (100ns intervals) | 48 bits (ms) | | Random bits | 74 bits | 74 bits | | Sorted | Time-ordered | Time-ordered | | Privacy | MAC address exposed | Random node identifier | | Adoption | Widely supported | Emerging standard | | Use case | Legacy systems | New applications |
Common use cases
- Database primary keys
- Event sourcing
- Distributed systems
- Time-series data
- Any application needing sortable unique IDs
FAQ
Is UUID v7 time-ordered? Yes, v7 UUIDs sort chronologically by generation time.
Can two machines generate the same UUID? Extremely unlikely with 74 random bits.
Is v7 better than v1? Yes, for most modern applications. v7 avoids privacy issues and works well with databases.
Can I convert v1 to v7? No, they have different structures. You'd need to generate a new v7.
How do I decode a v7 UUID? Extract the 48-bit timestamp, convert from Unix milliseconds to your local time.
Is v7 RFC 4122 compliant? No, v7 is defined in RFC 9562 (UUIDv7), not RFC 4122.
Should I use v7 for my database? Yes, v7 is excellent for database keys due to its time-based ordering.