UUID Generator - Generate Random UUID Online

Free UUID generator supporting UUID v4 and UUID v7. Generate random unique identifiers instantly in your browser.

Version: V4Format: 8-4-4-4-12 hexadecimal digits

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What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier used to uniquely identify information in computer systems. UUIDs are standardized by the Open Software Foundation (OSF) and are widely used in databases, distributed systems, APIs, and software development. Our free UUID generator creates random UUIDs instantly in your browser — no data is ever sent to a server.

UUID v4 vs UUID v7

UUID v4 (Random)

Generated from random or pseudo-random numbers. The most common UUID version, ideal for general-purpose unique identification. Contains 122 random bits and 6 version/variant bits.

UUID v7 (Timestamp-ordered)

Generates time-ordered UUIDs with a Unix timestamp in the first 48 bits followed by random bits. Better for database indexing since newer UUIDs are lexicographically sortable. Ideal for primary keys in modern databases.

UUID Examples

UUID v4 (Random)

550e8400-e29b-41d4-a716-446655440000

UUID v7 (Timestamp-based)

018f3e0c-a1b3-7000-8000-000000000000

How to Use UUID Generator

  1. 1

    Select UUID version — v4 for random, v7 for time-ordered UUIDs

  2. 2

    Choose how many UUIDs to generate (1, 5, 10, or 50)

  3. 3

    Click "Generate UUID" or "Generate Multiple" to create UUIDs

  4. 4

    Copy individual UUIDs or download all as a text file

Frequently Asked Questions

What is the difference between UUID v4 and v7?

UUID v4 is purely random — it uses random numbers for generation and makes no guarantees about ordering. UUID v7 includes a Unix timestamp in the first 48 bits, making it time-sortable. This is beneficial for database indexing since new records naturally sort to the end of the index. UUID v7 is the newer standard (RFC 9562, published 2024) and is increasingly recommended for database primary keys.

Are UUIDs really unique?

UUIDs have an extremely low probability of collision. A UUID v4 has 122 random bits, giving approximately 5.3 × 10^36 possible values. To have a 50% chance of at least one collision, you would need to generate about 2.7 × 10^18 UUIDs — equivalent to generating 1 billion UUIDs per second for 85 years.

Can I use UUIDs as database primary keys?

Yes, UUIDs are commonly used as database primary keys. UUID v7 is especially recommended for databases because its time-ordered nature improves index performance compared to v4. Major databases like PostgreSQL, MySQL, and SQLite all support UUID types natively.

Is my data sent to a server when I generate UUIDs?

No. All UUID generation happens entirely in your browser using JavaScript's Crypto API. No data is ever uploaded, stored, or shared. Your privacy is fully protected.