UUID Generator
Generate unique identifiers (UUIDs)
How to use
- Select UUID version (v1, v4)
- Click generate
- Copy the UUID
Use cases
- Database primary keys
- API identifiers
- Session management
- Unique ID generation
About the UUID Generator
A UUID (Universally Unique Identifier) is a 128-bit value used as a unique identifier without coordination between systems. v4 UUIDs are random (best for opaque IDs); v1 UUIDs are time-based (sortable by creation). This generator produces spec-compliant RFC 4122 v1 and v4 UUIDs using cryptographically secure randomness — many other online tools use Math.random, which is predictable and unsafe for security-sensitive use.
Features
- RFC 4122 v1 (time-based) and v4 (random)
- crypto.randomUUID when available — browser-native, FIPS-grade
- Batch generate up to 100 UUIDs in one click
- Copy one or copy all
- Version bits and variant bits set correctly
How it works
- Pick v1 or v4.
- Choose how many to generate (1–100).
- Click Generate.
- Copy a single UUID or copy all at once.
Frequently asked questions
What's the difference between v1 and v4?
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v1 encodes a timestamp and machine identifier — it's sortable by creation time but leaks info. v4 is fully random — collision-safe and opaque, the modern default.
Should I use UUID v7?
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v7 (time-ordered random) is excellent for database primary keys because it indexes efficiently. It's a 2024 RFC addition, increasingly supported — we're adding it in a follow-up release.
How random is v4?
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We use crypto.getRandomValues (or crypto.randomUUID when available), both backed by OS-level CSPRNGs. Collision probability for 122 random bits is astronomically low.
Can I generate thousands at once?
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We cap the UI at 100 per batch to keep the page responsive. For higher volumes, call crypto.randomUUID in your own script.
Are these globally unique?
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For v4, yes — the collision probability is ~1 in 2^122, practically zero. For v1, uniqueness depends on the machine ID + clock sequence; two processes on the same machine could theoretically collide.