UUID Generator

A UUID (Universally Unique Identifier) is a 128-bit (32 hex character) standard format used in software to generate identifiers that are globally unique without requiring a central coordinator.

UUID Generator

UUID v4 (Random)

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UUID Version Comparison

Version	Generation Method	Best For
v1	Timestamp + MAC address	When sequential ordering is needed
v3	MD5 hash (namespace-based)	URL-derived unique IDs
v4	Fully random	General use (most widely used)
v5	SHA-1 hash (namespace-based)	More secure alternative to v3

UUID v4 format: xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx (4: version indicator; y: one of 8, 9, a, b).
Collision probability: generating 1 billion UUIDs gives a collision chance of roughly 1 in a billion.

Code Examples

// JavaScript (modern browser)
crypto.randomUUID()

// Node.js with uuid library
import { v4 as uuidv4 } from 'uuid';
uuidv4(); // '9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d'

# Python
import uuid
str(uuid.uuid4())  # '110e8400-e29b-41d4-a716-446655440000'

-- PostgreSQL
SELECT gen_random_uuid();

UUID vs. ULID vs. NanoID

Format	Length	Sortable	Readability	Recommended When
UUID v4	36 chars	❌	Average	General purpose
ULID	26 chars	✅	Good	DB primary keys, sort needed
NanoID	21 chars	❌	Good	URLs, short IDs
Related Tools: Developer Utilities · Password Generator

UUID Generator: Free Instant UUID v4 Random Identifier

UUID Generator

UUID Generator

UUID Version Comparison

Code Examples

UUID vs. ULID vs. NanoID

OIYO Editorial