UUID Generator
Generate UUIDs v1-v7, Nil, and Max. All versions supported including v7 for databases. Bulk generation and validation.
Bulk Generation
Validate UUID
How to Use
Generate UUID
Click "Generate UUID" to create a new random UUID (v4).
Copy to Clipboard
Click "Copy" to copy the UUID for use in your code or database.
Bulk Generate
Enter a count (1-100) and click "Generate Bulk" for multiple UUIDs at once.
What is a UUID?
A UUID (Universally Unique Identifier), also known as a GUID, is a 128-bit identifier that is practically unique across all systems. UUIDs are formatted as 32 hexadecimal digits in five groups:
550e8400-e29b-41d4-a716-446655440000
FAQ
What is a UUID?
A UUID is a 128-bit identifier guaranteed to be unique across all systems. It's commonly used for database primary keys, session IDs, and API references.
Which UUID version should I use?
- v1 (Timestamp) - Uses timestamp + MAC address. Good for tracing but exposes creation time.
- v2 (DCE Security) - Rarely used. For POSIX systems with UID/GID requirements.
- v3 (MD5 Name-based) - Deterministic from namespace + name. Same input = same UUID.
- v4 (Random) - Most common choice. Fully random, no metadata.
- v5 (SHA-1 Name-based) - Like v3 but uses SHA-1. Preferred over v3.
- v6 (Reordered Time) - Like v1 but reordered for better database sorting.
- v7 (Unix Timestamp) - Best for databases. Sortable by creation time, excellent for indexing.
What's the difference between UUID and GUID?
UUID and GUID are the same thing. UUID is the standard term, while GUID is Microsoft's terminology. Both follow the same format.
What are Nil and Max UUIDs?
Nil UUID is all zeros (00000000-0000-0000-0000-000000000000) and represents an empty or null UUID. Max UUID is all ones (ffffffff-ffff-ffff-ffff-ffffffffffff) and is useful for range queries as the maximum possible value.
Can two UUIDs be the same?
Theoretically possible, but the probability is astronomically low (about 1 in 2^122). For practical purposes, collisions are considered impossible.