UUID Generator
Generate UUID v4 (Universally Unique Identifiers) instantly. Perfect for database IDs, API keys, and unique identifiers.
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UUID Version 4 (Random)
This tool generates RFC 4122 compliant UUID v4 identifiers using cryptographically secure random number generation. Each UUID has 122 random bits, making collisions extremely unlikely (1 in 5.3 × 10³⁶).
What is a UUID (Universally Unique Identifier)?
A Universally Unique Identifier (UUID) is a 128-bit number used to identify information in computer systems. While the probability that a UUID will be duplicated is not zero, it is close enough to zero to be negligible for almost all practical purposes.
The standard representation of a UUID is a string of 32 hexadecimal digits, displayed in five groups separated by hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000).
Understanding UUID Version 4
This tool specifically generates UUID v4, which is based entirely on randomness. Unlike v1 (which uses time and MAC addresses) or v3/v5 (which use namespace names), v4 uses a cryptographically secure random number generator to fill 122 of the 128 bits.
Collision Probability: To have a 50% chance of a collision, you would need to generate 1 billion UUIDs per second for about 85 years. For most applications, UUIDs are effectively unique.
When to Use UUIDs in Your Project
- Database Primary Keys: UUIDs allow you to generate IDs on the client-side or across distributed systems without needing a central database to increment an integer.
- Session Identifiers: Secure, random identifiers for tracking user sessions.
- API Keys and Auth Tokens: The high entropy of UUID v4 makes them excellent for temporary tokens and secure references.
- Resource Links: Creating unique, non-guessable URLs for sharing private content.
🔒 Privacy Commitment
Like all tools in the Dev Tool Kit, this UUID Generator operates 100% client-side. Your data is processed locally in your browser and is never sent to our servers. Privacy is not just a feature; it's our core architecture.