How to Use UUIDs

Best practices for implementing UUIDs in your applications

When to Use UUIDs

Choose UUIDs when you need unique identifiers across distributed systems

✅ Good Use Cases

Distributed database primary keys
API resource identifiers
Session and request tracking
File and document naming
Microservices communication

⚠️ Consider Carefully

High-performance applications (use integers)
Human-readable identifiers needed
Storage space is critical
Sequential ordering is required

Best Practices

Use UUID v4 for General Purpose

UUID v4 is the most common choice for general applications due to its randomness and security.

Perfect for Database Keys

UUIDs work excellently as primary keys in distributed systems and prevent ID conflicts.

Ideal for APIs

Use UUIDs for request tracking, session management, and resource identification.

Consider Storage Size

UUIDs are 128-bit (16 bytes), larger than sequential integers. Consider this for performance.

Implementation Examples

How to generate UUIDs in popular programming languages

JavaScript

Node.js with crypto module

const crypto = require('crypto');

// Generate UUID v4
const uuid = crypto.randomUUID();
console.log(uuid); // e.g., 'f47ac10b-58cc-4372-a567-0e02b2c3d479'

Python

Using uuid module

import uuid

# Generate UUID v4
uuid_v4 = uuid.uuid4()
print(str(uuid_v4))  # e.g., 'f47ac10b-58cc-4372-a567-0e02b2c3d479'

# Generate UUID v1 (timestamp-based)
uuid_v1 = uuid.uuid1()
print(str(uuid_v1))

Java

Using java.util.UUID

import java.util.UUID;

// Generate UUID v4
UUID uuid = UUID.randomUUID();
System.out.println(uuid.toString());

// Parse UUID from string
UUID parsed = UUID.fromString("f47ac10b-58cc-4372-a567-0e02b2c3d479");

C#

Using System.Guid

using System;

// Generate new GUID (equivalent to UUID v4)
Guid guid = Guid.NewGuid();
Console.WriteLine(guid.ToString());

// Parse GUID from string
Guid parsed = Guid.Parse("f47ac10b-58cc-4372-a567-0e02b2c3d479");

UUID Version Comparison

Choose the right UUID version for your use case

Version	Method	Uniqueness	Use Case	Privacy
UUID v4	Random	Very High	General purpose	High
UUID v1	Timestamp + MAC	High	Sortable IDs	Low
GUID	Random (v4)	Very High	Microsoft systems	High

Quick Start Guide

Generate UUID v4

Most popular choice for general applications. Cryptographically secure and random.

Generate UUID v1

Timestamp-based UUIDs. Sortable but may reveal system information.

Generate GUID

Microsoft-style GUIDs. Compatible with .NET and Windows systems.

Start Using UUIDs in Your Project

Generate UUIDs for your applications with our free tools. Choose the version that best fits your needs.

Generate UUID v4 Learn About UUIDs