How to Generate a UUID in Any Programming Language

Every database row needs an ID. The question is whether that ID should come from the database (auto-increment) or be generated by your application (UUID). When you need IDs generated without database interaction, or across multiple systems, UUIDs are the answer.

Generate a UUID Now

In JavaScript

crypto.randomUUID() is built into modern browsers and Node.js 15+. No library needed. Returns a UUID v4 string. For older environments: import { v4 as uuidv4 } from 'uuid' and call uuidv4(). The uuid package is well-maintained and has 5M+ weekly downloads.

In Python

import uuid; str(uuid.uuid4()) — built into Python's standard library. For UUID v7 (time-ordered), the python-uuid7 package provides uuid7.uuid7(). No installation needed for v4.

In Other Languages

• Java: UUID.randomUUID().toString() — built-in
• Go: google/uuid package (uuid.New())
• Rust: uuid crate with rand feature
• PHP: Str::uuid() in Laravel, or ramsey/uuid package
• SQL (PostgreSQL): gen_random_uuid() — built-in

UUID v7 for Database Primary Keys

UUID v4 is random, which means adjacent insertions go to different parts of a B-tree index, causing fragmentation and slower queries over time. UUID v7 includes a millisecond timestamp prefix, so recently-created records have adjacent UUIDs. They sort chronologically. Database index performance is much closer to auto-increment integers. If you're using UUIDs as primary keys in PostgreSQL or MySQL, v7 is worth using.