Free Online UUID Generator

v4

Generate random UUIDs instantly. Bulk generation and multiple formats supported.

Options
Configure UUID generation
Generated UUIDs
1 UUID generated
573c7724-2e12-4d68-8083-fadb1852e3d9

About UUIDs

UUIDs (Universally Unique Identifiers) are 128-bit identifiers that are guaranteed to be unique across space and time. They are commonly used in distributed systems where unique IDs need to be generated without coordination between nodes.

UUID Format

A standard UUID looks like: 550e8400-e29b-41d4-a716-446655440000
It consists of 32 hexadecimal digits displayed in 5 groups separated by hyphens, in the form 8-4-4-4-12 for a total of 36 characters.

Common Use Cases

  • Database primary keys
  • Session identifiers
  • Distributed system identifiers
  • File naming
  • API request correlation IDs

Frequently Asked Questions

UUID (Universally Unique Identifier) is a 128-bit identifier that is unique across all devices and time. UUIDs are commonly used as database primary keys, session IDs, and for distributed systems.

UUID v4 is a randomly generated UUID. It uses random or pseudo-random numbers to generate the identifier, making collisions extremely unlikely (1 in 5.3 × 10^36).

Yes, we use the crypto.randomUUID() API which provides cryptographically secure random UUIDs, or a fallback implementation using crypto.getRandomValues().

Yes! Use the "No hyphens" option to generate UUIDs in the format without dashes (32 characters instead of 36).

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The Complete Guide

About the UUID Generator

A UUID (Universally Unique Identifier) is a 128-bit value used to identify information in computer systems. UUIDs are everywhere: primary keys in databases, session IDs, filenames, distributed system events, message IDs — anywhere you need a globally-unique identifier without asking a central authority for the next number.

There are five UUID versions specified by RFC 4122, but two dominate in practice: version 4 (random) uses 122 bits of entropy from a CSPRNG and is the default for most applications; version 1 (time-based) encodes the current timestamp plus a MAC address, making it sortable but exposing information about when and where it was generated.

Our UUID Generator produces v4 UUIDs using window.crypto.getRandomValues() — the same source Node.js uses for randomUUID(). We format the output in the standard 8-4-4-4-12 hex form (like 550e8400-e29b-41d4-a716-446655440000) and optionally in uppercase, without hyphens, or as JSON arrays for batch use.

How to use UUID Generator

1

Click Generate

A single UUID v4 appears instantly. Click again for a fresh one — each is independent and effectively guaranteed unique.

2

Generate in bulk

Change the count to any number from 1 to 1000 to generate many UUIDs at once — useful when seeding a database or generating test data.

3

Pick a format

Standard hyphenated (default), uppercase, no-hyphens, brace-wrapped ({...}), or JSON array. Some databases prefer no hyphens; some languages expect braces.

4

Copy or download

Copy individual UUIDs to clipboard or download the whole batch as .txt, .csv, or .json for import into your app.

5

Use in your code

UUIDs work as primary keys in SQL and NoSQL databases, message IDs in queues, request IDs in logs, and file names on cloud storage.

Common Use Cases

Database primary keys

UUIDs let you generate IDs client-side or across microservices without a central sequence generator. Great for distributed systems where auto-increment doesn't work.

Session and request tokens

Assign a UUID to every incoming HTTP request so you can trace a single user journey through your logs across services.

Unique filenames

When users upload files, prefix or replace the filename with a UUID to avoid collisions and prevent enumeration attacks.

Distributed event IDs

Kafka, RabbitMQ, and other message brokers use IDs to dedupe events. UUIDs make cross-machine dedupe trivial.

Test data seeding

Generate 100 UUIDs for creating realistic test users, orders, or documents in a staging database.

React key props

When rendering lists of items that don't have natural IDs (e.g., form field arrays), a UUID gives React a stable key.

Frequently Asked Questions

Astronomically small. With 122 bits of randomness, you would need to generate roughly 2^61 UUIDs before there's a 50% chance of collision. That's 2.3 quintillion UUIDs — more than every atom in a small city. In practice, treat v4 UUIDs as unique.

Related Tools You May Like

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Hash Generator →

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Timestamp Converter →

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