GUID V4 - Random-Based Identifier (Recommended)
GUID v4 is the most widely used random-based identifier. Learn about its structure, collision probability, advantages and why it is recommended for general-purpose applications.
How to Generate UUIDs in Java
Generate UUIDs in Java with UUID.randomUUID() for v4 and a library such as uuid-creator for v7 when you need sortable identifiers.
Recommendation: use UUID v4 for fully random IDs, and UUID v7 when you want time ordering without giving up randomness.
How to generate UUID v4 in Java
import java.util.UUID;
UUID id = UUID.randomUUID();
System.out.println(id);
// Example: 7d444840-9dc0-11d1-b245-5ffdce74fad2How to generate UUID v7 in Java
The Java standard library does not currently expose UUID v7 directly, so most projects use a library.
// Maven: com.github.f4b6a3:uuid-creator
import com.github.f4b6a3.uuid.UuidCreator;
import java.util.UUID;
UUID id = UuidCreator.getTimeOrderedEpoch();
System.out.println(id);Native support notes
- Java uses UUID terminology, not GUID terminology.
- UUID v4 is native through
UUID.randomUUID(). - UUID v7 normally requires a third-party library.
- Other UUID versions are not part of the common standard-library workflow.
Practical notes
Frequently Asked Questions
Not in the common standard-library API. Most Java projects use a dedicated UUID library for v7 generation.
Use v4 for simple random identifiers. Use v7 when insert order and chronological sorting matter more.
Learn more
These articles expand on related concepts, formats and practical considerations.