UUID Generator
Generate random UUID v4 identifiers. Bulk generation, multiple format options, and version information.
1 – 100 UUIDs
Set your options and click Generate UUID.
About This Tool
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify information in computer systems. This generator creates UUID Version 4 identifiers, which are randomly generated using cryptographically secure random numbers (crypto.getRandomValues).
UUID v4 Structure: A standard UUID v4 follows the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx — 32 hexadecimal digits with 4 hyphens, totaling 36 characters. The "4" indicates version 4, and "y" (8, 9, A, or B) indicates the variant.
Format Options: Choose between lowercase (standard), uppercase, or no-hyphens format. The no-hyphens format is useful for systems that don't support hyphens in identifiers, or when you need a compact 32-character hex string.
Bulk Generation: Need multiple UUIDs? Generate up to 100 at once. Each UUID is independently generated using fresh random values, so there's no predictable pattern between them.
Collision Probability: With 2^122 possible random UUIDv4 values, the probability of generating a duplicate is astronomically low — you'd need to generate ~2.71 × 10^18 UUIDs to have a 50% chance of a single collision.
Common uses for UUIDs include: database primary keys, distributed system identifiers, session tokens, file names, request/transaction IDs, and anywhere you need a globally unique identifier without a central coordination service.