UUID Generator

Overview

UUID Generator is a browser-based utility that creates universally unique identifiers (UUIDs) in four official variants—v1, v3, v4 and v5—allowing you to tag data or resources with collision-free IDs.

The tool ships as pure client-side JavaScript, so every UUID is produced locally on your device. No calls are made to external APIs, keeping sensitive workflows private and offline-friendly.

You can fine-tune output style in real time: switch to uppercase for code constants, strip dashes for compact storage, or wrap the string in braces for C-style literals. Namespace versions (v3 & v5) use DNS, URL, OID, X.500 or a custom UUID as the seed, producing deterministic results for repeatable builds.

Whether you are seeding test databases, tagging log events, provisioning cloud resources or generating activation keys, this lightweight generator delivers standards-compliant UUIDs in a single click.

About & Background

UUIDs (RFC 4122) provide 122 bits of randomness or namespace-derived entropy, making accidental collisions astronomically unlikely.

The utility leverages the battle-tested uuid npm package (8.3.2) to mirror the algorithms found in popular back-end libraries, ensuring identical results across languages and environments.

Key Features

The generator focuses on speed, privacy and convenience.

Instant output – Generates on page load or on-demand.
Client-only processing – No data leaves the browser.
Namespace support – Deterministic v3 & v5 IDs with DNS, URL, OID, X.500 or custom UUID seeds.
Flexible formatting – Uppercase, dashless, or brace-wrapped variants.
One-click copy – Clipboard API integration for frictionless pasting.

UUID Variants & Algorithms

Behind the scenes, each version follows a distinct recipe.

Version	Basis / Algorithm	Deterministic?	Typical Use
v1	Timestamp + MAC / node ID + random clock sequence	No	Legacy systems, ordered indexes
v3	MD5(name, namespace)	Yes	Repeatable IDs for the same input
v4	122 bits of cryptographic randomness	No	Default choice for unique keys
v5	SHA-1(name, namespace)	Yes	Deterministic IDs when MD5 is discouraged

Step-by-Step Guide

Follow this quick workflow to produce and use an ID.

1Select a UUID Version in the drop-down menu.
2If you picked v3 or v5, enter a Name (e.g. example.com) and its Namespace.
3Toggle Uppercase, Remove dashes or Include braces to match your coding style.
4Hit Generate; a fresh UUID appears in the read-only field.
5Click Copy to clipboard and paste it where needed.

When to Use Each Version

Choose the variant that best fits your constraints.

Version 4 – Random

Pick v4 for most new projects: ultra-low collision risk, no input requirements.

Version 3 / 5 – Namespace

Need repeatable IDs? Use v3 (MD5) or v5 (SHA-1); the same name + namespace always yields the same UUID.

Version 1 – Time-based

Legacy stacks sometimes rely on timestamp-sortable v1 UUIDs; avoid when MAC disclosure is a concern.

FAQ

Find quick answers to common questions.

Is the generator safe for production secrets?

Yes. All calculations run in your browser; no data is transmitted or stored remotely.

Why would I remove dashes?

Dashless UUIDs save four bytes and can be friendlier for file names or URL paths.

Which namespace should I choose?

Use DNS for domains, URL for full addresses, or supply a custom UUID to create your own domain of uniqueness.