What is a GUID or UUID?

A GUID or UUID is a 128-bit identifier used to create values that are highly unlikely to collide across systems.

When should I use UUID v4?

UUID v4 is useful for test data, database identifiers, distributed systems, public IDs, logs, and request tracing.

Developer generator tool

GUID Generator Online

Generate free UUID v4 and GUID values for databases, APIs, logs, file names, test data, .NET apps, and distributed systems. Values are created locally in your browser.

UUID v4BulkCopyPrivate

Generate GUIDs

Choose count and output style, then generate copy-ready identifiers.

Count Generate 1 to 500 GUID values at once.

Uppercase letters Add braces Include hyphens Quote values

Private by design. GUIDs are generated in your browser. QuickDeveloperTools does not store generated values.

Generated UUID v4 Output

0 values ready

GUID and UUID guide

Free GUID Generator for Developers, Databases, and APIs

More generators

Database IDs

Generate UUID v4 values for seed data, SQL Server UNIQUEIDENTIFIER columns, test records, and distributed inserts.

API and Logs

Create request IDs, correlation IDs, resource identifiers, mock payload IDs, and trace-friendly values.

Flexible Formatting

Use lowercase, uppercase, braces, quoted values, or hyphen-free IDs depending on your platform requirements.

Generate GUIDs in Code

const id = crypto.randomUUID();

using System;

var id = Guid.NewGuid();

SELECT NEWID(); -- SQL Server UNIQUEIDENTIFIER

Related QuickDeveloperTools

GUID Generator FAQ

GUID and UUID Questions

What is a GUID?

GUID stands for Globally Unique Identifier. It is a 128-bit value commonly used to uniquely identify records, objects, files, sessions, and resources.

What is a UUID?

UUID stands for Universally Unique Identifier. GUID and UUID usually refer to the same 128-bit identifier format, especially when using UUID version 4 values.

What is UUID v4?

UUID v4 is a randomly generated UUID. It is widely used because it does not need a central database or sequence generator to create unique-looking identifiers.

Can I generate multiple GUIDs at once?

Yes. Enter the number of values you need and generate up to 500 GUID or UUID values in one batch.

Are GUIDs generated locally?

Yes. This generator uses your browser to create UUID values. The generated identifiers are not uploaded or stored by QuickDeveloperTools.

Can I remove hyphens from GUIDs?

Yes. Turn off the Include hyphens option to generate compact GUID values without dash separators.

Can I generate uppercase GUIDs?

Yes. Enable Uppercase letters if your database, code style, or documentation prefers uppercase UUID values.

When should developers use GUIDs?

GUIDs are useful for database primary keys, public IDs, request correlation IDs, log tracing, test data, file names, and distributed systems.