How to Generate UUIDs in JavaScript, Python, Java, and Go

Meta Description: Generate UUIDs in any language. Copy-paste code examples for JavaScript, Python, Java, Go, Rust, PHP, and command line UUID generation.

Need a UUID in your code? Here's how to generate them in every major programming language—with copy-paste examples you can use right now.

JavaScript / TypeScript

Built-in: crypto.randomUUID() (Recommended)

Available in browsers (Chrome 92+, Firefox 95+, Safari 15.4+) and Node.js 16+:

// Generate a v4 UUID
const id = crypto.randomUUID();
console.log(id);
// 'f47ac10b-58cc-4372-a567-0e02b2c3d479'

Node.js crypto module

import { randomUUID } from 'crypto';

const id = randomUUID();
console.log(id);
// 'f47ac10b-58cc-4372-a567-0e02b2c3d479'

uuid package (v4, v1, v7)

For more control or older environments:

npm install uuid

import { v4 as uuidv4, v1 as uuidv1, v7 as uuidv7 } from 'uuid';

// v4 - random
const randomId = uuidv4();
// 'f47ac10b-58cc-4372-a567-0e02b2c3d479'

// v1 - timestamp + MAC
const timeId = uuidv1();
// '6ba7b810-9dad-11d1-80b4-00c04fd430c8'

// v7 - sortable timestamp (uuid v9+)
const sortableId = uuidv7();
// '0184e0e9-5b50-7dd8-8a0b-9e5d8a8b3f2a'

// Validate
import { validate } from 'uuid';
validate(randomId); // true
validate('not-a-uuid'); // false

TypeScript Types

import { v4 as uuidv4 } from 'uuid';

// UUID is just a string
const id: string = uuidv4();

// Type-safe alternative
type UUID = `${string}-${string}-${string}-${string}-${string}`;

function createUser(id: UUID, name: string) {
  // ...
}

Python

Built-in uuid module (Recommended)

import uuid

# v4 - random (most common)
random_id = uuid.uuid4()
print(random_id)
# f47ac10b-58cc-4372-a567-0e02b2c3d479

# v1 - timestamp + MAC
time_id = uuid.uuid1()
print(time_id)
# 6ba7b810-9dad-11d1-80b4-00c04fd430c8

# Convert to string
str_id = str(random_id)
hex_id = random_id.hex  # without hyphens

# Parse from string
parsed = uuid.UUID('f47ac10b-58cc-4372-a567-0e02b2c3d479')

# Validate
def is_valid_uuid(val):
    try:
        uuid.UUID(str(val))
        return True
    except ValueError:
        return False

uuid7 package (v7 support)

pip install uuid7

import uuid7

# v7 - sortable timestamp
sortable_id = uuid7.uuid7()
print(sortable_id)
# 0184e0e9-5b50-7dd8-8a0b-9e5d8a8b3f2a

uuid-utils package (All versions, faster)

pip install uuid-utils

from uuid_utils import uuid4, uuid7

id_v4 = uuid4()
id_v7 = uuid7()

Java

java.util.UUID (Built-in)

import java.util.UUID;

public class UUIDExample {
    public static void main(String[] args) {
        // v4 - random
        UUID randomId = UUID.randomUUID();
        System.out.println(randomId);
        // f47ac10b-58cc-4372-a567-0e02b2c3d479

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

        // Get components
        long mostSig = randomId.getMostSignificantBits();
        long leastSig = randomId.getLeastSignificantBits();

        // Version
        int version = randomId.version();  // 4

        // Compare
        boolean equal = randomId.equals(parsed);
    }
}

UUID v7 (com.github.f4b6a3:uuid-creator)

<!-- Maven -->
<dependency>
    <groupId>com.github.f4b6a3</groupId>
    <artifactId>uuid-creator</artifactId>
    <version>5.3.3</version>
</dependency>

import com.github.f4b6a3.uuid.UuidCreator;

// v7 - sortable timestamp
UUID sortableId = UuidCreator.getTimeOrderedEpoch();

// v1 - timestamp + MAC
UUID timeId = UuidCreator.getTimeBased();

// v4 - random
UUID randomId = UuidCreator.getRandomBased();

Go

google/uuid package (Recommended)

go get github.com/google/uuid

package main

import (
    "fmt"
    "github.com/google/uuid"
)

func main() {
    // v4 - random
    id := uuid.New()
    fmt.Println(id)
    // f47ac10b-58cc-4372-a567-0e02b2c3d479

    // String conversion
    str := id.String()

    // Parse from string
    parsed, err := uuid.Parse("f47ac10b-58cc-4372-a567-0e02b2c3d479")
    if err != nil {
        panic(err)
    }

    // Validate
    _, err = uuid.Parse("not-a-uuid")
    if err != nil {
        fmt.Println("Invalid UUID")
    }

    // v1 - timestamp + MAC
    v1, _ := uuid.NewUUID()

    // v7 - sortable timestamp (uuid v2+)
    v7, _ := uuid.NewV7()
}

Rust

uuid crate

# Cargo.toml
[dependencies]
uuid = { version = "1.4", features = ["v4", "v7"] }

use uuid::Uuid;

fn main() {
    // v4 - random
    let id = Uuid::new_v4();
    println!("{}", id);
    // f47ac10b-58cc-4372-a567-0e02b2c3d479

    // v7 - sortable timestamp
    let id_v7 = Uuid::now_v7();

    // Parse from string
    let parsed = Uuid::parse_str("f47ac10b-58cc-4372-a567-0e02b2c3d479")
        .expect("Invalid UUID");

    // String conversion
    let str_id = id.to_string();
    let hyphenated = id.hyphenated().to_string();
    let simple = id.simple().to_string();  // no hyphens
}

PHP

Built-in (PHP 8.1+)

<?php
// v4 - random (no external dependencies)
function uuid4(): string {
    $data = random_bytes(16);
    $data[6] = chr(ord($data[6]) & 0x0f | 0x40); // Version 4
    $data[8] = chr(ord($data[8]) & 0x3f | 0x80); // Variant

    return vsprintf('%s%s-%s-%s-%s-%s%s%s', str_split(bin2hex($data), 4));
}

echo uuid4();
// f47ac10b-58cc-4372-a567-0e02b2c3d479

ramsey/uuid (Full-featured)

composer require ramsey/uuid

<?php
use Ramsey\Uuid\Uuid;

// v4 - random
$uuid = Uuid::uuid4();
echo $uuid->toString();
// f47ac10b-58cc-4372-a567-0e02b2c3d479

// v1 - timestamp + MAC
$uuid1 = Uuid::uuid1();

// v7 - sortable timestamp
$uuid7 = Uuid::uuid7();

// Parse
$parsed = Uuid::fromString('f47ac10b-58cc-4372-a567-0e02b2c3d479');

// Validate
$isValid = Uuid::isValid('f47ac10b-58cc-4372-a567-0e02b2c3d479'); // true

C# / .NET

System.Guid (Built-in)

using System;

// Generate v4 UUID (Microsoft calls it GUID)
Guid id = Guid.NewGuid();
Console.WriteLine(id);
// f47ac10b-58cc-4372-a567-0e02b2c3d479

// String conversion
string str = id.ToString();
string noDashes = id.ToString("N");  // f47ac10b58cc4372a5670e02b2c3d479

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

// TryParse for validation
bool isValid = Guid.TryParse("f47ac10b-58cc-4372-a567-0e02b2c3d479", out _);

Command Line

uuidgen (macOS, Linux)

# Generate v4 UUID
uuidgen
# F47AC10B-58CC-4372-A567-0E02B2C3D479

# Lowercase (pipe through tr)
uuidgen | tr '[:upper:]' '[:lower:]'
# f47ac10b-58cc-4372-a567-0e02b2c3d479

# Generate multiple
for i in {1..10}; do uuidgen; done

Python one-liner

python -c "import uuid; print(uuid.uuid4())"

Node.js one-liner

node -e "console.log(require('crypto').randomUUID())"

Validation Regex

For validating UUIDs in your code:

// JavaScript
const UUID_REGEX = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;

function isValidUUID(str) {
    return UUID_REGEX.test(str);
}

# Python
import re

UUID_PATTERN = re.compile(
    r'^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$',
    re.IGNORECASE
)

def is_valid_uuid(s):
    return bool(UUID_PATTERN.match(s))

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FAQ

Which library should I use for production?

Use built-in libraries when possible (JavaScript crypto.randomUUID, Python uuid, Java UUID, Go google/uuid). They're well-tested and don't add dependencies.

How do I generate UUIDs without dependencies?

Every example above has a built-in option. JavaScript, Python, Java, Go, C#, and PHP all have native UUID support.

Are UUIDs thread-safe to generate?

Yes. All standard library implementations use thread-safe random number generators. You can generate UUIDs from multiple threads without coordination.

How do I store UUIDs in databases?

• PostgreSQL: Native UUID type
• MySQL: BINARY(16) or CHAR(36)
• SQLite: TEXT or BLOB(16)
• MongoDB: Native UUID type

Can I use UUIDs as passwords or tokens?

UUIDs are unique but not secret. For security tokens, use cryptographically secure random bytes (e.g., secrets.token_urlsafe(32) in Python). UUIDs are fine for session IDs if combined with proper session security.

Related Tools:

• UUID Generator — Generate UUIDs instantly
• UUID Validator — Check UUID format
• Bulk UUID Generator — Generate thousands at once