UUID Generator
A UUID generator is a free online tool that creates universally unique identifiers (UUIDs) β 128-bit random strings used in databases, APIs, and distributed systems.
How to use UUID Generator
- Choose count β Pick how many UUIDs to generate (1-100).
- Generate β Click to create random v4 UUIDs.
- Copy β Copy one or all UUIDs to your clipboard.
Key features
- UUID v4 standard
- Bulk generation (up to 100)
- One-click copy all
- Cryptographically random
- Works offline
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify objects in a distributed system. The most common format is a 36-character string like '550e8400-e29b-41d4-a716-446655440000' with 32 hex digits separated by hyphens. UUIDs are used in databases (primary keys), APIs (request IDs), file systems, and anywhere uniqueness across systems is critical.
UUID Versions Explained
UUID v1 β time-based + MAC address (predictable). UUID v3 β MD5 hash of namespace + name (deterministic). UUID v4 β fully random (most common today). UUID v5 β SHA-1 hash of namespace + name (deterministic). UUID v7 β new standard combining time-ordering with randomness (emerging standard for databases).
When to Use UUIDs
Use UUIDs when IDs must be unique across multiple systems, when you can't predict the number of records, or when you don't want sequential IDs (which leak information about volume and creation order). For high-scale databases, UUID v7 offers better index performance than v4.
Why Use Our Generator?
Our generator uses the Web Crypto API β the same cryptographically secure random number generator used in security software. Every UUID is generated locally in your browser. Nothing is transmitted. And you can generate up to 100 at once.
Pro tips
- Use UUID v4 for most modern applications
- Consider UUID v7 if you need time-ordered IDs
- Store UUIDs as 16-byte binary for efficiency
- Never use UUIDs as passwords or secrets β they're not secret
Common use cases
- Database primary keys
- API request tracking
- Distributed system coordination
- Session identifiers
- File naming to prevent collisions
Frequently asked questions
What is a UUID?+
A UUID (Universally Unique Identifier) is a 128-bit label used to identify information in computer systems. Version 4 UUIDs are randomly generated.
Are these truly unique?+
Yes β v4 UUIDs have about 5.3 Γ 10^36 possible values, making collisions practically impossible.
What's the difference between UUID and GUID?+
None β they're the same thing. Microsoft uses GUID, the rest of the world uses UUID.
Is it free?+
Yes, 100% free.
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