UUID Generator

Generate cryptographically random UUID v4 identifiers instantly. Bulk generate up to 100, toggle uppercase or lowercase, and copy individual or all UUIDs with one click.

Click Generate to create UUID v4 identifiers

Instantly generate one or many UUID v4 identifiers for databases, APIs, session tokens, and anywhere you need a guaranteed unique ID. Every UUID uses cryptographic randomness for collision-free results.

When to Use the UUID Generator

Use UUIDs as primary keys in databases, as unique request identifiers in APIs, for session or correlation IDs in distributed systems, or as filenames when you need guaranteed uniqueness without a central registry. For secure user-facing tokens rather than internal IDs, the password generator produces stronger random strings.

UUID Generator Tips

  • Generate UUIDs in bulk when seeding a database — select your count and copy all at once.
  • Use lowercase UUIDs for consistency with RFC 4122 and most programming libraries.
  • UUID v4 is ideal for most use cases. Only consider v1 (time-based) if you specifically need time-ordering.
  • Store UUIDs as native UUID types in PostgreSQL rather than text — it uses half the storage and is faster to index.

Frequently Asked Questions

Are the UUIDs truly unique? ▾

Yes. UUID v4 uses 122 bits of randomness from the Web Crypto API. The probability of generating a duplicate is roughly 1 in 5.3 billion billion — effectively zero.

What is a UUID v4? ▾

UUID v4 is a 128-bit identifier formatted as 32 hex digits in five groups (8-4-4-4-12) separated by hyphens. The "4" in the third group indicates the version, and the first digit of the fourth group is 8, 9, a, or b to indicate the variant.

Can I use these UUIDs in production? ▾

Absolutely. The UUIDs are generated using crypto.randomUUID() or crypto.getRandomValues(), the same source of randomness used by databases and backend frameworks.

What is the difference between UUID and GUID? ▾

They are the same thing. UUID (Universally Unique Identifier) is the standard term. GUID (Globally Unique Identifier) is the term Microsoft uses. The format and generation method are identical.

Should I use uppercase or lowercase UUIDs? ▾

RFC 4122 recommends lowercase for output, but UUIDs are case-insensitive for comparison. Use whichever your system expects — most databases and APIs accept either.

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