UUID v4 Generator Online
Generate universally unique identifiers (UUIDs) in various formats. Supports bulk generation and customization.
Generated UUIDs
▶About UUID Generator
A UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify resources in distributed systems without requiring a central authority. The most common version, UUID v4, generates identifiers from cryptographically secure random numbers, providing a collision probability so low it is effectively zero.
This free online UUID generator creates RFC 4122-compliant v4 UUIDs using the browser's crypto.randomUUID() API. You can generate single or bulk UUIDs with one click, choose between standard hyphenated and compact formats, and copy results instantly.
Common use cases: generating primary keys for database records, creating unique session or transaction identifiers, assigning correlation IDs for distributed tracing, producing idempotency keys for payment and API requests, and generating unique filenames for uploads.
▶Frequently Asked Questions
▶What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit label used to identify resources across distributed systems without a central authority. A standard UUID looks like 550e8400-e29b-41d4-a716-446655440000.
▶What is UUID v4?
UUID v4 generates identifiers using cryptographically secure random numbers. The collision probability is about 1 in 5.3 x 10^36 — virtually impossible.
▶When should I use UUIDs vs auto-increment IDs?
Use UUIDs when you need globally unique IDs without database coordination, such as in distributed systems, microservices, or offline-first apps. Auto-increment IDs are simpler but require a central database.
▶Can I generate UUIDs in bulk?
Yes. Set the quantity you need and click Generate. This tool can create hundreds of UUIDs at once, with one-click copy for the entire batch.