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UUID/GUID Generator

Generate universally unique identifiers (UUID) in different versions. Free tool to create UUID v1, v4, v7, NIL UUID and GUID for your projects.

Standard UUID

Standard universally unique identifier (version 4)

UUID Version 1

Based on timestamp and MAC address (time-identifiable)

UUID Version 4

Completely random (most common and recommended)

UUID Version 7

Sortable timestamp-based (newest, ideal for databases)

NIL UUID / Empty UUID

Empty UUID with all digits zeroed (00000000-0000-0000-0000-000000000000)

00000000-0000-0000-0000-000000000000

GUID

Microsoft Globally Unique Identifier (equivalent to UUID in uppercase)

What is UUID?

UUID (Universally Unique Identifier) is a 128-bit identifier used to uniquely identify information in computer systems. With a UUID, you have statistical guarantee that the identifier will be unique, without the need for central coordination. They are widely used in databases, distributed systems, APIs and software development.

UUID Versions

UUID v1 - Timestamp + MAC

Generated from current timestamp and machine's MAC address. Useful when you need to know when the UUID was created, but may expose hardware information.

UUID v4 - Random

Completely random (or pseudo-random). It's the most common and recommended version for most use cases, offering high entropy and no information leakage.

UUID v7 - Sortable Timestamp

The newest version (2022), based on Unix timestamp in milliseconds. Allows natural ordering by creation time, ideal for use as primary key in databases and distributed systems.

NIL UUID - Empty

Special UUID with all bits set to zero (00000000-0000-0000-0000-000000000000). Used to represent absence of value or as initial default value.

GUID - Microsoft

GUID (Globally Unique Identifier) is the term used by Microsoft for UUID. Technically identical, but usually represented in uppercase letters in Windows environments.

Use Cases

  • •Unique identifiers for database records
  • •Session IDs in web applications and APIs
  • •Document and file identification in distributed systems
  • •Primary keys in microservices and distributed architectures
  • •Identification tokens in authentication systems
  • •Transaction IDs in financial and e-commerce systems
  • •Message identifiers in queue and event systems
  • •Unique references in cache and storage systems

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