UUID Generator — Generate Unique Identifiers Online

Tool processing happens entirely in your browser. Your input is never sent to our servers.

Version

Count

Format

UUID Validator

Paste a UUID to check validity and detect its version.

NIL UUID:00000000-0000-0000-0000-000000000000

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UUID vs GUID vs ULID — What's the Difference?

A UUID (Universally Unique Identifier) is a 128-bit identifier designed to be unique without requiring a central authority. The standard format is xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx — 32 hexadecimal characters with four hyphens.

UUID Versions:

v1 (Timestamp + MAC): Uses the current timestamp and the machine's MAC address. Provides rough chronological ordering but can expose system information. Rarely used in new applications.

v4 (Random): Generated entirely from random numbers. The most widely used version — simple, fast, and with negligible collision probability. Our generator uses the Web Crypto API for cryptographic randomness.

v7 (Timestamp + Random): The modern recommendation for database primary keys. Embeds a Unix timestamp in milliseconds in the first 48 bits, followed by random data. This means v7 UUIDs sort chronologically, giving you the best of both worlds: globally unique identifiers with the database indexing performance of sequential IDs.

GUID is simply Microsoft's name for UUID. Functionally identical, often written with braces: {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}.

ULID (Universally Unique Lexicographically Sortable Identifier) is an alternative format: 26 characters using Crockford's Base32. Like UUID v7, ULIDs are timestamp-prefixed and sortable, but more compact.

For encoding generated UUIDs in URL parameters, use the URL Encoder/Decoder. To include UUIDs in JSON payloads, the JSON Formatter helps verify the structure.

How to Use This UUID Generator

Paste or type your input in the editor above
Click the action button or the tool will process automatically
View the result in the output panel
Copy the result with one click using the Copy button

Frequently Asked Questions

Yes. UUID v4 generation uses the Web Crypto API (crypto.randomUUID or crypto.getRandomValues), which provides cryptographically secure random numbers suitable for security-sensitive applications.

Yes. You can generate 1, 5, 10, 25, 50, or 100 UUIDs in a single click. All are generated instantly in your browser.

UUID v4 (random) is the most common choice. UUID v7 (timestamp-based) is better for database primary keys because it is sortable. UUID v1 is legacy and rarely recommended for new projects.

No. UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) are the same thing. GUID is the term used primarily in Microsoft ecosystems.