UUID v4 Generator — Random UUID Online Free
UUID v4 is the most widely used UUID version. All 122 bits are randomly generated, making collisions statistically impossible for any practical application.
Example UUID v4
550e8400-e29b-41d4-a716-446655440000Generate UUID v4
6cba2a7b-e2a3-47e1-9f95-f0e0d6e4be69Bit breakdown
FAQ
What is a UUID v4?
UUID v4 is a randomly generated 128-bit identifier. The version (4) is encoded in bits 12–15 of the third group, and the variant bits are set in the first two bits of the fourth group. All other 122 bits are randomly generated.
How likely are UUID v4 collisions?
Generating 1 billion UUIDs per second for 100 years gives a 50% chance of a single collision. For any practical database, the probability is effectively zero.
When should I use UUID v4 instead of v7?
Use v4 when you don't need sortability — e.g., session tokens, one-off identifiers, or anywhere insertion order doesn't matter. Use v7 when you're storing IDs in a database index and want chronological sorting.
Need a different UUID version? The full generator supports v1, v4, v5, v7, and ULID.
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