UUID Generator
Generate RFC 4122 version 4 UUIDs locally in your browser.
About UUID v4
UUID v4 values are randomly generated identifiers commonly used for database keys and request ids. Generation happens entirely in your browser.
Learn More About UUID Generation
Complete Guide to UUID Generation: Understanding Unique Identifiers
Explore the world of UUIDs, learn about different versions, understand their applications in modern software development, and discover best practices for implementation.
About this UUID Generator
Generate RFC 4122 version 4 UUIDs (GUIDs) instantly. UUIDs are 128-bit unique identifiers used in databases, APIs, distributed systems, and anywhere you need a globally unique ID. Our generator creates cryptographically random UUIDs in your browser—no server round-trip. Copy one or many UUIDs with one click.
Key Features
Generate RFC 4122 v4 UUIDs
Cryptographically random
Copy single or multiple UUIDs
Generate one or many at once
Standard format (8-4-4-4-12 hex)
Works entirely in your browser
No signup or API required
How to Use
Click 'Generate UUID' to create a new UUID
Use 'Generate multiple' to create several at once
Click copy to copy a UUID to the clipboard
Generate new UUIDs as needed for your app or database
Popular Use Cases
Primary keys in databases
Request or correlation IDs in APIs
Session and token identifiers
Distributed system IDs
File or resource identifiers
Testing and development
Logging and tracing
Tips & Best Practices
UUIDs are 36 characters including hyphens (e.g. 550e8400-e29b-41d4-a716-446655440000)
v4 UUIDs are random; no two should ever collide in practice
Store as string or as 16 bytes (128 bits) in databases
Use for any identifier that must be unique across systems
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit value that is virtually guaranteed to be unique. RFC 4122 v4 UUIDs are randomly generated and used as unique IDs in software.
What is the difference between UUID and GUID?
GUID (Globally Unique Identifier) is Microsoft's term for the same concept. UUID and GUID are used interchangeably; both refer to the same standard format.
Are these UUIDs secure for tokens?
v4 UUIDs are random and unpredictable, which makes them suitable for non-guessable IDs. For security-sensitive tokens (e.g. session secrets), use a dedicated token or secret generator.
Can two UUIDs ever be the same?
The probability is astronomically low (2^122 possible values). In practice, UUIDs are considered unique without coordination between systems.
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