UUID Generator
Generate cryptographically secure UUID v4 identifiers. Create single or multiple UUIDs with formatting options, all processed in your browser.
How to Use the UUID Generator
- Select how many UUIDs you want to generate (1, 5, 10, or 25).
- Choose your formatting options: uppercase or lowercase, with or without hyphens.
- Click the Generate button to create new UUIDs.
- Copy individual UUIDs or use Copy All to get them all at once.
About UUID Generator
A UUID (Universally Unique Identifier) is a 128-bit identifier that is guaranteed to be unique across all devices and time. UUID version 4 uses random or pseudo-random numbers, generated using the Web Crypto API for cryptographic security. UUIDs are commonly used as primary keys in databases, session identifiers, correlation IDs in distributed systems, and anywhere a unique identifier is needed without a central authority. The standard format is 8-4-4-4-12 hexadecimal digits separated by hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000). This tool generates compliant RFC 4122 version 4 UUIDs entirely in your browser.
Frequently Asked Questions
While not mathematically impossible to collide, the probability is astronomically low. With 122 random bits, you would need to generate approximately 2.71 quintillion UUIDs to have a 50% chance of a single collision.
UUID v1 uses timestamp and MAC address, v3 uses MD5 hashing, v4 uses random numbers, and v5 uses SHA-1 hashing. Version 4 is the most commonly used as it provides strong uniqueness without exposing system information.
Yes, this tool uses crypto.randomUUID() which leverages the Web Crypto API for cryptographically secure random number generation. All generation happens client-side in your browser.