UUID Generator
Generate random UUIDs (Universally Unique Identifiers)
Version 4 UUIDs are generated using random numbers. They're suitable for most applications.
About Our UUID Generator
Our free online UUID (Universally Unique Identifier) generator helps you create unique identifiers for your applications, databases, and systems. UUIDs are 128-bit identifiers that are virtually guaranteed to be unique across time and space.
A UUID is a 128-bit number used to uniquely identify information in computer systems. UUIDs are standardized by the Open Software Foundation (OSF) and are commonly used in software development. They are typically displayed as 32 hexadecimal digits, shown in five groups separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters.
Version 4 (Random)
Generated using random numbers. Most commonly used type, suitable for most applications. Completely random with no meaningful structure.
Version 1 (Time-based)
Generated based on timestamp and MAC address. Sortable by creation time but may reveal system information.
Uniqueness
Designed to be unique across different systems, perfect for distributed systems.
No Central Authority
Can be generated independently by any system without coordination.
Database-Friendly
Can be used as primary keys, eliminating issues with auto-incrementing IDs.
Security
Version 4 UUIDs are random and don't reveal system or data information.
URL-Safe
Can be safely used in URLs without encoding, ideal for REST APIs.
Common Use Cases
Use UUIDs as primary keys to ensure uniqueness across distributed systems.
Generate UUIDs for resources in REST APIs, making them globally unique.
Use UUIDs for session identifiers to ensure security and prevent hijacking.
Generate unique file names using UUIDs to prevent conflicts.
Use UUIDs for transaction identifiers in payment systems.
Track events in analytics systems with unique identifiers.
Frequently Asked Questions
UUID v1 (time-based) includes a timestamp and MAC address, making them sortable by creation time but potentially revealing system information. UUID v4 (random) are completely random and don't contain any meaningful information, making them more secure and suitable for most use cases.
The probability of a UUID collision is extremely low. For version 4 UUIDs, the chance of collision is about 1 in 5.3 × 10^36 for generating 1 billion UUIDs. In practice, collisions are so unlikely that they can be considered impossible for most applications.
UUIDs are typically displayed in lowercase, but the standard allows both uppercase and lowercase hexadecimal characters. Our generator produces lowercase UUIDs, which is the most common convention. When comparing UUIDs, they should be compared case-insensitively.
Yes, UUIDs are URL-safe and can be used directly in URLs without encoding. They're commonly used in REST APIs for resource identifiers, like /api/users/550e8400-e29b-41d4-a716-446655440000.
Version 4 UUIDs are random and don't reveal information about the system or data they identify. However, they shouldn't be used as the sole security measure. Always use proper authentication and authorization in addition to UUIDs.
Most modern databases support UUID data types. PostgreSQL has a native UUID type, MySQL 8.0+ supports UUID functions, and other databases typically use CHAR(36) or BINARY(16) to store UUIDs. Always check your database documentation for the recommended storage method.