UUID/GUID Generator
Generate unique identifiers (UUID/GUID) with custom format support
Select the UUID version to generate
Number of UUIDs to generate (1-100)
0 UUIDs
UUID Validator
UUID/GUID Generator Documentation
What is UUID/GUID?
UUID (Universally Unique Identifier) or GUID (Globally Unique Identifier) is a 128-bit number used to identify information in computer systems. UUIDs are designed to be unique across both space and time without requiring a central authority.
UUIDs are commonly used as database primary keys, unique identifiers in distributed systems, session management, and generating unique file names.
UUID Versions
Version 1 (Timestamp-based)
Generated using current timestamp and MAC address. Contains time information and can be traced back to the generating machine.
Version 4 (Random)
Generated using random or pseudo-random numbers. Most commonly used version due to simplicity and no privacy concerns.
NIL UUID
A special UUID consisting of all zeros, used to represent a null or empty UUID value.
UUID Format
UUIDs are typically represented as a 36-character string in the format: 8-4-4-4-12 hexadecimal digits
- M: Represents the UUID version (1, 4, etc.)
- N: Represents the UUID variant (always 8, 9, a, or b)
- x: Any hexadecimal digit (0-9, a-f)
Common Use Cases
Database Primary Keys
Use UUIDs as primary keys to ensure uniqueness in distributed databases without central coordination.
Session Management
Generate unique session identifiers for web applications to securely track user sessions.
File Naming
Create unique file names for uploaded files to prevent conflicts and ensure file uniqueness.
Distributed Systems
Identify entities in distributed systems without requiring coordination between nodes.
Best Practices
- Use Version 4 (Random) for most applications for simplicity and privacy
- Use Version 1 only when timestamp information is needed
- Store UUIDs in binary format for better database performance
- Validate UUID format before processing to ensure data integrity
- Consider collision probability: while extremely low, always handle duplicates gracefully
- Use lowercase format for consistency unless uppercase is specifically required