UUID Generator
Generate RFC 4122 v1 and v4 compliant unique bulk identifiers locally.
UUID Specifications & Collision Math
What is the difference between UUID v1 and v4?
UUID v1 is a time-based identifier that merges a high-resolution 60-bit Gregorian timestamp, clock sequence, and a 48-bit spatial node identifier (usually the network hardware MAC address or random equivalent). UUID v4 is a fully random identifier that uses cryptographically secure hardware entropy to populate 122 bits of random state. v4 is widely preferred for database primary keys because it leaks zero network or temporal metadata.
What is the probability of a UUID v4 collision?
UUID v4 yields 2¹²² (or approximately 5.3 × 10³⁶) possible unique states. The collision math is governed by the Birthday Paradox. To have a 50% probability of a single duplicate collision, you would need to generate 125 billion billion (or 2.7 × 10¹⁸) identifiers. It is mathematically virtually impossible to encounter a duplicate in production systems.
About SuperUtility UUID Generator
SuperUtility offers an industrial-grade bulk UUID (Universally Unique Identifier) generator. A UUID is a 128-bit label used to identify information in computer systems without relying on a central authority. SuperUtility fully complies with the RFC 4122 specification, offering both time-based Version 1 and fully random Version 4 formats.
Our generator features rich customization, allowing you to choose between uppercase or lowercase formatting, toggle hyphens on or off, define exact generation batch sizes (up to 50 in a single click), and instantly export your dataset into a standard flat text file for developer scripting or database seeding.
Frequently Asked Questions
What is the difference between UUID v1 and v4?
• UUID Version 1: Generated using a combination of the current system timestamp, clock sequence numbers, and your device's MAC address. It guarantees chronological uniqueness but exposes timestamp details in the string.
• UUID Version 4: Generated using pure, cryptographically secure pseudo-random values. It provides complete anonymity and extreme entropy, making it the industry standard for modern application keys.
What is the probability of a UUID v4 collision?
Extremely close to zero. A UUID v4 contains 122 bits of pure randomness, meaning there are 2^122 (or approximately 5.3 x 10^36) possible combinations. To have a 50% chance of a single collision, you would need to generate 1 billion UUIDs *every second* for 85 consecutive years.
Can I generate bulk identifiers without internet?
Yes. All identifier calculations occur entirely client-side using pure JavaScript browser loops. None of the generated strings are sent to our servers or stored in any database, meaning your identifiers are entirely yours and completely secure.
Are these UUIDs safe for primary keys in databases?
Yes, absolutely! Since our random source uses the secure Web Cryptography API (window.crypto), the keys are completely cryptographically sound, making them perfect for MongoDB, PostgreSQL, MySQL, or Redis primary record keys.
UUID v1 and v4 Format Comparison Examples
UUID Version 4 (Random CSPRNG)
The most common format for general-purpose application keys:
// Standard Lowercase with hyphens f81d4fae-7dec-11d0-a765-00a0c91e6bf6 // Uppercase Format F81D4FAE-7DEC-11D0-A765-00A0C91E6BF6 // Hyphenless Format (32-Character Hex string) f81d4fae7dec11d0a76500a0c91e6bf6
UUID Version 1 (Time-Based)
Ideal if you want your keys to have a built-in chronological sorting component:
// Time-based sorted UUID string 1ec8f700-1c2a-11ed-b57d-31776c5bfae7