UUID Generator

Random UUID

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v4

2404e393-3272-4cd7-bac2-cce6ed7c3a36

Time based UUID

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v6

1f181e61-784d-6b00-a0ce-8ad0b2e12e43

UUID v7

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Time + Random

Uses a 48-bit Unix epoch timestamp (millisecond precision) followed by random bits. Time-sortable and optimized for better database indexing than V1. Considered the modern best practice.

019f7055-4cb0-7628-b877-9a6fe9519f2d

UUID v6

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Reordered Time-based

Time-based like V1 but reorders the bits to be monotonically increasing (better for database indexing). Does not expose the MAC address (often uses a random node ID instead).

1f181e61-784d-6b01-acf6-87dff97d2b03

UUID v4

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Random (Pseudo-random numbers)

Maximum unpredictability and privacy. Not sortable by time. Higher (but still very low) theoretical collision chance compared to time-based.

819037aa-c10d-4ce8-b223-c5cbe96d5fce

UUID v1

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Time-based + MAC Address

High uniqueness, sortable by time. Privacy concern due to including the generating machine's MAC address.

1784db02-81e6-11f1-a0ce-8bd0b2e12e43