UUID Generator
Generate bulk Version 4 UUIDs instantly. Cryptographically strong and collision-safe for your database keys.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit value used to uniquely identify information in computer systems. Unlike auto-incrementing integers (1, 2, 3...), UUIDs are generated without a central authority.
UUID Versions Explained
Version 4 (Random)
Based on random numbers. This is the most common version used in modern applications because it preserves privacy (no MAC address) and is simple to generate.
Format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
Version 1 (Time-based)
Generated using the current time and your computer's MAC address.Privacy Risk: It reveals exactly when the ID was created and which computer created it.
Version 3 & 5 (Name-based)
Generated by hashing a namespace and a name (v3 uses MD5, v5 uses SHA-1). Useful when you need the same input to always produce the same UUID.
The Math of Collisions
"Can two people generate the same UUID?"
With Version 4, there are 2122 possible combinations. That's 5.3 undecillion IDs.
If you generated 1 billion UUIDs per second for 85 years, you would have only a 50% chance of generating a single collision.
UUID vs. Integer ID
Use UUID when:
- You have distributed systems.
- You want to hide total user counts from URLs.
- You might merge databases later.
Use Integer when:
- Performance is critical (faster indexing).
- Storage space is extremely limited (32-bit vs 128-bit).
- IDs must be easy for humans to type.
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