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 Kotlin
Generate UUIDs in Kotlin with java.util.UUID for v4 and a library-backed approach for v7 on the JVM.
Recommendation: use native UUID v4 for simplicity, and add UUID v7 through a library when chronological ordering matters in your application.
How to generate UUID v4 in Kotlin
import java.util.UUID
val id = UUID.randomUUID()
println(id)How to generate UUID v7 in Kotlin
// Gradle: implementation("com.github.f4b6a3:uuid-creator:...")
import com.github.f4b6a3.uuid.UuidCreator
val id = UuidCreator.getTimeOrderedEpoch()
println(id)Native support notes
- Kotlin/JVM inherits Java UUID behavior.
- UUID v4 is native through the JVM UUID class.
- UUID v7 is usually library-based.
Practical notes
Frequently Asked Questions
On the JVM, it is mostly the same. Kotlin calls into the same underlying Java UUID APIs and libraries.
In most Kotlin/JVM projects, UUID v7 is added through a library rather than a standard built-in API.
Learn more
These articles expand on related concepts, formats and practical considerations.