UUID Generator
Generate universally unique identifiers (UUIDs) instantly. Support for both UUID v1 (timestamp-based) and v4 (random) formats.
How to Generate UUIDs
Step 1: Generate UUID
Click "Generate New" to create a fresh UUID. Each UUID is cryptographically random and guaranteed to be unique.
Step 2: Copy UUID
Click "Copy" to copy the UUID to your clipboard. The UUID is ready to use in databases, APIs, or applications.
Step 3: Use in Your Project
Paste the UUID wherever you need a unique identifier - database primary keys, file names, session IDs, or API tokens.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit value used to uniquely identify information in computer systems. UUIDs are designed to be unique across space and time without requiring a central authority.
Our generator creates Version 4 UUIDs, which use random or pseudo-random numbers. The probability of generating duplicate UUIDs is negligibly small (about 1 in 5.3 x 10³⁶).
UUID Format
xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
Where x is any hexadecimal digit and y is one of 8, 9, A, or B.
Frequently Asked Questions
Are UUIDs truly unique?
While not mathematically guaranteed, UUID Version 4 has such a low collision probability (1 in 5.3 x 10³⁶) that they're considered unique for all practical purposes. You'd need to generate billions of UUIDs per second for thousands of years to have a reasonable chance of collision.
When should I use UUIDs?
Use UUIDs when you need unique identifiers without a central coordinator, for distributed systems, database primary keys, session tokens, file names, API keys, or when merging data from multiple sources.
What's the difference between UUID versions?
Version 1 uses MAC address and timestamp, Version 3 uses MD5 hash, Version 4 (our generator) uses random numbers, and Version 5 uses SHA-1 hash. Version 4 is most common for general use due to its simplicity and strong randomness.
Can I use UUIDs as database primary keys?
Yes! UUIDs make excellent primary keys, especially in distributed systems. They eliminate the need for centralized ID generation and allow offline record creation. However, they're larger than integers, so consider performance implications for very large tables.
Are UUIDs secure for sensitive applications?
Version 4 UUIDs are cryptographically random and safe for most applications. However, for security-critical applications like authentication tokens, consider using dedicated cryptographic libraries for additional security features.
Common UUID use cases
UUIDs are perfect for:
- Database primary keys in distributed systems
- Session identifiers for web applications
- Unique file names to prevent conflicts
- API request tracking and correlation IDs
- Transaction IDs in financial systems
- Entity identifiers in microservices
- Message IDs in queue systems