UUID Generator
Generate v4 UUIDs instantly
Click Generate to create UUIDs
Uses crypto.randomUUID() for cryptographically secure UUIDs
About UUID v4
UUID v4 (Universally Unique Identifier version 4) uses random numbers to generate unique identifiers. The probability of collision is astronomically low (1 in 2^122).
About UUID Generator (v4)
1What is it?
Generate cryptographically secure UUID version 4 identifiers instantly. UUIDs (Universally Unique Identifiers) are 128-bit numbers used as unique identifiers in databases, distributed systems, and applications. This tool uses your browser's cryptographic random number generator for true randomness.
2Use Cases
- Generate primary keys for database records
- Create unique identifiers for distributed systems
- Generate session IDs for user tracking
- Create correlation IDs for request tracing
- Generate unique file or resource names
- Create test data with realistic IDs
- Replace auto-increment IDs for security
3Examples
Standard UUID v4
Input
Generate UUID
Output
550e8400-e29b-41d4-a716-446655440000
Multiple UUIDs
Input
Bulk generate
Output
550e8400-e29b-41d4-a716-446655440000 6ba7b810-9dad-11d1-80b4-00c04fd430c8 ...
?Frequently Asked Questions
Are these UUIDs truly random and unique?
Yes. This tool uses crypto.randomUUID() which provides cryptographically secure random numbers. The probability of generating a duplicate is approximately 1 in 2^122 - effectively impossible in practice.
What's the difference between UUID and GUID?
They're essentially the same thing. UUID (Universally Unique Identifier) is the standard term in RFC 4122. GUID (Globally Unique Identifier) is Microsoft's term for the same concept. Both refer to the same 128-bit identifier format.
Should I use UUIDs as database primary keys?
UUIDs offer benefits: no central coordination needed, harder to guess/enumerate, work in distributed systems. Drawbacks: larger than integers (16 bytes vs 4-8), random UUIDs can cause index fragmentation. Consider UUID v7 for time-ordered UUIDs that index better.
Why version 4 specifically?
UUID v4 is completely random, making it simple and secure. V1 uses timestamps+MAC address (can leak info), V3/V5 are hash-based (deterministic), V6/V7 are newer time-based variants. V4 is the most commonly used for general purposes.
Can I use UUIDs in URLs?
Yes, UUIDs are URL-safe as they only contain hexadecimal characters (0-9, a-f) and hyphens. You can even remove the hyphens for shorter URLs (32 characters instead of 36).