UUID v1 v1 · time
The first UUID version, generated from time and a node (usually a MAC address).
Overview
It combines a timestamp (in 100-nanosecond units, based on the year 1582), a clock sequence, and a node identifier. It carries ordering information, but can expose the generating machine's MAC address, which raises privacy concerns.
Structure
| Bit length | 128 |
|---|---|
| Character length | 36 |
| Format | hex 8-4-4-4-12 |
| Sortable | Partial |
| Random-based | No |
When to use
Used when legacy system compatibility is required or when tracking the creation time and machine matters. For new projects, v7 is usually the better choice.