UUID Generator (v4)

What is a UUID (Universally Unique Identifier)?

A Universally Unique Identifier (UUID), standardized in IETF RFC 4122, is a 128-bit value used to uniquely identify entities in software systems without requiring central registration or coordination between database servers.

A standard canonical UUID is represented as 32 hexadecimal digits displayed in five hyphen-delimited groups formatted as 8-4-4-4-12:

In a Version 4 UUID, the digit at position 13 is always fixed to 4 (indicating Version 4), while the variant bits at position 17 always start with 8, 9, a, or b (RFC 4122 variant).

UUID Version Comparison

Generating UUID v4 in Code

Native JavaScript (Browser & Node.js 16+)

// Built-in WebCrypto API
const uniqueId = crypto.randomUUID();
console.log("Generated UUID:", uniqueId);

Python 3 Standard Library

import uuid

# Generate a cryptographically random UUID v4
random_id = uuid.uuid4()
print("UUID String:", str(random_id))

Go (Golang)

package main

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

func main() {
    id := uuid.New()
    fmt.Println("UUID v4:", id.String())
}

Frequently Asked Questions