RFC 4122 · Bulk Generate · Custom Format · Free

Free Online UUID Generator

Generate RFC 4122 compliant UUIDs v4 instantly — one at a time or in bulk. Customize format, case and separators.

Click "Generate" to create your first UUID

UUID v4 — Cryptographically random

Bulk Generated UUIDs — 0 total

The UUID generator developers trust

Fast, RFC-compliant, and endlessly flexible.

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Cryptographically Random

Uses the Web Crypto API (crypto.randomUUID) for true cryptographic randomness.

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Bulk Generation

Generate up to 1,000 UUIDs at once, copy them all or download as a .txt file.

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Format Options

Standard, no-hyphen, URN or braces format — uppercase or lowercase.

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Auto-Refresh

Enable auto-refresh to generate a new UUID every second for testing purposes.

How It Works

Three Simple Steps

1

Choose UUID version

Select UUID v1 (time-based), v4 (random), or v5 (namespace-based) based on your needs.

2

Set quantity

Choose how many UUIDs to generate — from a single ID to bulk batches of thousands.

3

Copy the UUIDs

Click Copy All to grab all generated UUIDs, or copy individual ones with a single click.

Frequently Asked Questions

What is a UUID?
UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 8-4-4-4-12 hexadecimal characters.
What is UUID v4?
UUID v4 is randomly generated — the most commonly used version for unique record identifiers.
Are UUIDs truly unique?
UUID v4 has 2^122 possible values. The probability of a collision is astronomically small.
Is my data sent to a server?
No. UUIDs are generated entirely in your browser using the crypto.randomUUID() API.
Should I use UUID or auto-increment IDs?
UUIDs are better for distributed systems. Auto-increment is simpler for single databases.

Uuid Generator — Complete Guide

This free online uuid generator tool is designed to work entirely in your browser — no uploads, no waiting, no software installation needed. It's fast, private, and completely free to use without any account or subscription.

💡 Use UUID v4 by default

UUID v4 is the safest default — fully random, no information about the generating machine embedded.

💡 Database primary keys

UUIDs as database primary keys work well in distributed systems where multiple services generate IDs independently.

💡 API resource identifiers

Use UUIDs as public-facing resource IDs in REST APIs — they prevent enumeration attacks.

💡 Format consistency

Store UUIDs as lowercase strings without braces — 550e8400-e29b... is standard UUID format.

UUID generation is fundamental in software development for creating unique identifiers for database records, API resources, and distributed systems.

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