Generate universally unique identifiers (UUIDs) instantly in your browser. Supports v4, bulk generation, and custom formatting.
Professional UUID generation with enterprise-grade features
Uses Web Crypto API for truly random UUID v4 generation with 122 bits of randomness.
All UUIDs generated locally in your browser. No data sent to any server.
Generate up to 100 UUIDs at once for database seeding, testing, or development.
Toggle between uppercase and lowercase. Copy individual or all UUIDs instantly.
Instant generation with no network latency. Works offline after initial page load.
Generates valid UUID v4 identifiers following the RFC 4122 specification.
Common questions about UUID generation
A UUID (Universally Unique Identifier) is a 128-bit identifier that is unique across all devices and time. Use UUIDs as primary keys in databases, for distributed systems, API identifiers, session tokens, and anywhere you need guaranteed unique identifiers without a central authority.
UUID v1 is time-based, v3 and v5 are name-based (using MD5 and SHA-1 respectively), v4 is randomly generated, and v7 is time-ordered. UUID v4 is the most commonly used version as it provides 122 bits of randomness with an extremely low collision probability.
UUID v4 has 2^122 possible values. The probability of collision is astronomically low — you would need to generate 2.71 quintillion UUIDs to have a 50% chance of a single collision. For practical purposes, UUID v4 values are unique.
Yes. We use the Web Crypto API (crypto.randomUUID()) which provides cryptographically secure random number generation. All generation happens locally in your browser — no data is ever sent to our servers.
UUIDs are excellent for distributed databases and microservices where auto-increment IDs can collide. However, UUID v4 can cause index fragmentation in B-tree indexes. Consider UUID v7 (time-ordered) for better database performance, or use UUIDs as secondary identifiers alongside auto-increment primary keys.
The standard UUID format is 8-4-4-4-12 hexadecimal characters separated by hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000). The total length is 36 characters including hyphens, or 32 hexadecimal digits.