Free Online UUID Generator

Generate random UUID v4 identifiers instantly. Cryptographically secure, v4, v7 ...

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Random. The default. 122 random bits from crypto, practically impossible to collide.

Pick a version and press Generate to create unique identifiers

UUID versions at a glance

UUID v4Random. The default. 122 random bits from crypto, practically impossible to collide.
UUID v7Time ordered. A millisecond timestamp leads, so values sort by creation time and index well.
UUID v1Time based. Timestamp plus a random node (no real MAC address is used).
UUID NILThe special all zero UUID, used as a placeholder or empty value.

Quick answer

A UUID (Universally Unique Identifier) is a 128-bit value written as 32 hex digits in the 8-4-4-4-12 pattern, used as a unique ID that is practically impossible to collide. This tool creates them entirely in your browser: version 4 draws its bits from the Web Crypto random source, and you can generate up to 100 at once, switch to time-ordered v7 or v1, toggle uppercase or hyphens, then copy any single one, copy all, or download them as a text file.

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Generator Features

v4 Random UUIDs - RFC 4122 compliant random UUIDs from crypto.getRandomValues
v7 and v1 Support - Time-ordered v7 (RFC 9562) and classic time-based v1
NIL UUID - Generate the special all-zeros UUID as a placeholder
Case and Hyphen Toggles - Uppercase, no-hyphen, braces, and urn:uuid output
Copy One or All - Click a row to copy it, or copy the whole batch
Download as .txt - Export every generated UUID to a text file

Why Use Free Online UUID Generator?

Cryptographically Secure

v4 UUIDs use the Web Crypto random source, not Math.random, so they are safe for real IDs.

Bulk in One Click

Generate 1 to 100 UUIDs at once, ideal for seeding a database or building test data.

v4, v7 and v1

Pick random v4, time-ordered v7 for better index locality, classic v1, or the NIL UUID.

100% In Your Browser

Everything runs locally. No UUID is ever sent to a server, and it works offline.

Common Uses for the UUID Generator

Database Primary Keys

Use v4 or v7 UUIDs as primary keys in distributed databases for guaranteed uniqueness.

API Identifiers

Generate unique resource IDs for REST APIs, microservices, and idempotency keys.

Session and Request IDs

Create unique session tokens and trace IDs for authentication and logging.

Test and Seed Data

Bulk generate up to 100 UUIDs and download them to seed test databases and mocks.

How It Works

1

Pick a version

Start with v4 (random). Switch to v7 or v1 if you need time-ordered IDs, or NIL for a placeholder.

2

Set count and format

Choose how many (1 to 100), then toggle uppercase, hyphens, or wrap in braces or urn:uuid form.

3

Generate, then copy or download

Press Generate. Click any row to copy it, use Copy all, or download every UUID as a .txt file.

Tips and Best Practices

Use the Standard Format

The lowercase hyphenated form is the most widely supported across databases and languages, so keep hyphens on unless a URL or filename needs them removed.

Prefer v7 for Primary Keys

Because v7 is time-ordered, new rows insert near the end of the index instead of scattering across it, which reduces page splits and speeds up writes versus random v4.

v4 Is Not Sequential

v4 values are random and reveal no timestamp. If you need to sort by creation time or hide creation order, choose v7 or v1 accordingly.

Frequently Asked Questions

A UUID (Universally Unique Identifier) is a 128-bit value shown as 32 hexadecimal digits grouped 8-4-4-4-12, for example 550e8400-e29b-41d4-a716-446655440000. It gives every item a unique ID without any central coordination, which is why it is common for database keys, session IDs, and distributed systems.
Open this page, keep the default v4 version, set how many you want, and press Generate. Each UUID is created in your browser from the Web Crypto random source. You can then click a row to copy it, copy them all, or download the whole batch as a text file.
In practice, yes. A v4 UUID has 122 random bits, so you would need to generate about 2.7 quintillion of them to reach a 50 percent chance of even one collision. Because the bits come from a cryptographic random source rather than Math.random, the values are well distributed and safe to treat as unique.
They are the same thing. GUID (Globally Unique Identifier) is the name Microsoft uses for its implementation of the UUID standard. Both use the identical 8-4-4-4-12 format and can be used interchangeably, so a UUID generator is also a GUID generator.
v4 is fully random, so values are unpredictable but land in random positions in a database index. v7 puts a millisecond timestamp at the front, so new values sort after older ones. That time ordering keeps inserts near the end of an index and improves write performance for primary keys.
Yes. Turn off the Hyphens toggle to get a 32 character string with no dashes, which suits URLs and file names, and turn on Uppercase for Windows and Microsoft style output. You can also wrap the value in braces or the urn:uuid: prefix.
Yes. v4 and v7 use crypto.getRandomValues (or crypto.randomUUID), the browser cryptographic random source, and v1 uses a random node instead of your real MAC address. Nothing is uploaded, so every UUID stays on your device.

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