Generate UUID v1

Generate or decode a time-based UUID version 1.

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ToolUUID v1 Generator
Input
Output
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Preview

How it works

Version 1 stores a 100-nanosecond timestamp since 1582, a clock sequence, and a node identifier in the 128-bit UUID layout. Version and variant bits identify the interpretation.

  • The clock sequence handles clock rollback.
  • A random node can avoid exposing a hardware address.

Worked example

Single UUID v1
Generate one time-based UUID v1
Input
											1
Output
												d1860550-a082-11f1-ba4a-7e44cd55db3c

When to use this

Legacy systems, migrations, and forensic tools inspect version-1 UUIDs.

Edge cases

  • Clock rollback requires a sequence change.
  • Older node fields can reveal a hardware address.
  • UUID time uses 100-nanosecond ticks rather than Unix milliseconds.

References