Developer

UUID Generator

Generate secure random RFC 4122 Version 4 UUIDs and GUIDs in single or bulk batches.

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Fast, secure & processed 100% locally in your browser

About This UUID Generator

This UUID generator creates Universally Unique Identifiers, the 128-bit labels used across databases, APIs, distributed systems and application code to identify records without central coordination. The tool supports the three most common variants: UUID v4 (fully random), UUID v1 (time-based, incorporating the current timestamp and a node identifier), and UUID v7 (Unix-timestamp based, sorting chronologically while keeping a random tail). Because v4 is overwhelmingly the most popular choice for general work, it is the default. Every UUID is generated in your browser using the Web Crypto API, the same source of randomness browsers use for security-sensitive operations.

The generator is useful for developers seeding a database, testers creating sample data, teams preparing mock API responses, or anyone who needs a batch of unique identifiers quickly. You can generate up to a thousand UUIDs at once, apply common formatting rules (uppercase, braces, URN prefix, hyphens), copy them to the clipboard, and export the list as plain text, JSON or CSV. A built-in validator also lets you check any UUID you paste, showing its version, variant and whether it matches the standard 8-4-4-4-12 layout.

How to Use the UUID Generator

Choose the UUID version you need — v4 for random, v1 for time-based, or v7 for sortable time-based identifiers.
Enter how many UUIDs to generate (1 to 1000) or click a preset such as 5 or 100.
Adjust the output format — uppercase, hyphens, braces, or URN prefix — and pick a list separator.
Click Generate to produce the list. Results update instantly in the output panel.
Use Copy, Copy First, or the download buttons to move the UUIDs into your project.
Paste any existing UUID into the Validator below to check its version and validity.

Key Features

Three UUID versions: v4 (random), v1 (time-based) and v7 (Unix timestamp with random tail).
Batch generation: produce up to 1,000 UUIDs in a single click.
Cryptographically random: uses crypto.getRandomValues() and crypto.randomUUID() where available.
Output formatting: uppercase letters, hyphens, curly braces, URN prefix, and configurable list separators.
Built-in validator: paste any UUID and instantly see its version, variant and validity.
Multiple export formats: download as TXT, JSON or CSV, or copy the first UUID with one click.
Session history: a rolling list of your recent generations for quick reference.
Client-side only: all processing happens in your browser; nothing is sent to a server.

Frequently Asked Questions

What is the difference between UUID v1, v4 and v7?

UUID v4 is generated entirely from random bits and is the standard choice when you simply need a unique identifier. UUID v1 encodes the current timestamp along with a node (MAC-like) identifier, making it useful when you want some temporal ordering. UUID v7 was designed more recently: it uses a Unix timestamp for the first 48 bits so UUIDs sort roughly in creation order, followed by random bits. v4 remains the most widely adopted for general use.

Are the UUIDs generated here truly unique?

UUID v4 has 122 random bits (out of 128; 6 bits are fixed for the version and variant). With that many possible values, the probability of generating the same UUID twice is astronomically small — practical tools and databases treat v4 UUIDs as collision-free. Randomness is sourced from the browser’s Web Crypto API, which is designed for cryptographic quality.

Does UUID v1 leak my MAC address?

The original UUID v1 specification places a 48-bit node identifier in the last segment, historically derived from a machine’s MAC address. Browsers do not expose MAC addresses to JavaScript, so this generator fills that segment with random bytes instead. This means the v1 UUIDs produced here are time-based but do not expose hardware information.

Why might I use UUID v7 instead of v4?

v7 sorts by time, which is valuable when UUIDs are used as primary keys in a database. Sequential inserts are friendlier to B-tree indexes than the random ordering of v4, potentially reducing index fragmentation. If your database or framework supports UUID v7, it can be a good choice for new projects.

Is my data sent to any server?

No. Everything runs in your browser using JavaScript and the Web Crypto API. The UUIDs you generate, the UUIDs you paste into the validator, and the history list are all kept only in the current page’s memory — nothing is uploaded and nothing is stored after you close or refresh the page.