UUID Generator
Generate UUID v4 instantly. Bulk generate up to 50 UUIDs. Copy to clipboard.
Click Regenerate to generate UUIDs
How to Use
- Choose your UUID version — v4 (random, most commonly used) or v1 (time-based with MAC address). v4 is recommended for general-purpose unique identifiers like database primary keys and session IDs.
- Set the number of UUIDs you need (1 to 50) and click Generate. All UUIDs are created locally in your browser using cryptographically secure random values.
- Copy individual UUIDs by clicking the copy icon next to each one, or use Copy All to copy the entire batch. UUIDs are in the standard 8-4-4-4-12 hexadecimal format (e.g., 550e8400-e29b-41d4-a716-446655440000).
Frequently Asked Questions
- Are generated UUIDs truly unique?
- UUID v4 uses 122 bits of random data, producing 2^122 possible values (about 5.3 × 10^36). The probability of collision is astronomically low — you'd need to generate billions of UUIDs per second for millions of years to have a meaningful chance of collision.
- What's the difference between UUID v1 and v4?
- UUID v1 is based on the current timestamp and the generating machine's MAC address, which means it encodes when and where it was created. UUID v4 is fully random with no embedded metadata. v4 is preferred when you don't want to leak timing or machine info, while v1 can be useful for time-sortable IDs.
- What's the actual collision probability?
- With UUID v4, to reach a 50% probability of at least one collision you'd need to generate approximately 2.71 × 10^18 UUIDs. To put that in perspective: generating 1 billion UUIDs per second would take about 86 years to reach that point.