UUID Generator: v4 and v7

crypto.randomUUID() (v4) is built into browsers, Node.js, Deno and Bun. Native v7: Node.js 26.1+ and Bun 1.1.34+; elsewhere, use the uuid npm package, version 10+.

import { randomUUIDv7 } from "node:crypto"; // Node.js 26.1+
import { v7 } from "uuid"; // npm package

crypto.randomUUID(); // v4
randomUUIDv7(); // v7, Node.js
Bun.randomUUIDv7(); // v7, Bun
v7(); // v7, uuid package

uuid7() is in the standard library from Python 3.14; earlier versions need a third-party package.

import uuid
uuid.uuid4()  # v4
uuid.uuid7()  # v7, Python 3.14+

UUID.randomUUID() (v4) works in every Java version. JDK 26 adds UUID.ofEpochMillis() for v7; the bits after the timestamp are random, so UUIDs from the same millisecond are not in order. Older JDKs need a library such as java-uuid-generator 4.1+.

import java.util.UUID;
import com.fasterxml.uuid.Generators; // library, older JDKs

UUID v4 = UUID.randomUUID();
UUID v7 = UUID.ofEpochMillis(System.currentTimeMillis()); // JDK 26+
UUID v7Lib = Generators.timeBasedEpochGenerator().generate();

Uuid.random() (v4) is stable from Kotlin 2.4. Uuid.generateV7() exists from Kotlin 2.3 but is still experimental, so it needs an opt-in.

import kotlin.uuid.ExperimentalUuidApi
import kotlin.uuid.Uuid

@OptIn(ExperimentalUuidApi::class)
fun main() {
    val v4 = Uuid.random()
    val v7 = Uuid.generateV7() // Kotlin 2.3+
}

gen_random_uuid() is built in from version 13 and uuidv7() from 18; on older servers, generate v7 in the application.

SELECT gen_random_uuid();  -- v4, PostgreSQL 13+
SELECT uuidv7();           -- v7, PostgreSQL 18+
CREATE TABLE orders (id uuid PRIMARY KEY DEFAULT uuidv7());

The standard library has a uuid package from Go 1.27. Earlier versions need github.com/google/uuid.

import "uuid" // Go 1.27+
uuid.NewV4().String() // v4
uuid.NewV7().String() // v7