UUID Generator

Generate one or many UUID v4 identifiers. Copy them with one click or download the batch as a text file.

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How to Use the UUID Generator

Click Generate to create UUID v4 strings. Copy individual UUIDs or download all as a file.

About This Tool

A UUID (Universally Unique Identifier) is a 128-bit value formatted as 32 hexadecimal characters in five groups (8-4-4-4-12), like 550e8400-e29b-41d4-a716-446655440000. Version 4 UUIDs are generated from 122 bits of random data, making collisions astronomically unlikely — you could generate one billion UUIDs per second for 85 years before having a 50% chance of a single duplicate. UUIDs are the standard way to create unique identifiers in distributed systems where a central authority cannot assign sequential IDs. This generator produces RFC 4122-compliant v4 UUIDs using the browser’s cryptographic random number generator (crypto.getRandomValues). Generate single or bulk UUIDs for databases, API keys, session tokens, and file naming. Use alongside a generate SHA-256 hashes tool when you need content-derived identifiers instead of random ones, or a create strong random passwords tool when you need human-memorable auth secrets rather than machine IDs.

Frequently Asked Questions

Are generated UUIDs stored anywhere?

No. UUIDs are generated entirely in your browser and are never sent to any server.

How random are the generated UUIDs?

The generator uses crypto.getRandomValues() to produce RFC 4122-compliant version 4 UUIDs with 122 bits of cryptographically secure randomness.

Can I generate multiple UUIDs at once?

Yes. Switch to Bulk mode to generate up to 100 UUIDs at once. Copy them all or download as a .txt file.

What is the difference between UUID v1 and v4?

UUID v1 uses the current timestamp and the device’s MAC address, making it partially predictable and potentially a privacy concern. UUID v4 is generated entirely from random data, making it unpredictable and privacy-safe. UUID v4 is the most commonly used version in modern software.

Can two UUIDs ever collide?

Technically yes, but the probability is negligible. UUID v4 has 122 random bits, giving 5.3 × 10³⁶ possible values. You would need to generate about 2.71 × 10¹⁸ UUIDs (2.71 quintillion) for a 50% chance of one collision. For practical purposes, UUID v4 values are unique.

Created by The Toobits Team · Engineering & Editorial

Toobits is built, tested, and maintained by a small independent engineering team. Every tool is written in TypeScript, runs entirely in the browser, and is reviewed against its source formulas before publication.

Editorial policy · Updated April 2026

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