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GUID Generator

Create one or many secure random UUID version 4 identifiers, also commonly called GUIDs, entirely in your browser.

Quick generator

Basic GUID generator

Generate one lowercase, standard-format UUID version 4 using secure browser randomness.

ResultReady to generateGUID and UUID are commonly used names for the same 128-bit identifier format.

Advanced options

Custom GUID generator

Create up to 10,000 UUID v4 identifiers with your preferred case, format, affixes, and separator.

Generated GUIDs0 results
Choose your settings, then generate GUIDs.

Generation happens locally in your browser.

How to use this calculator

  1. Use the basic section for one lowercase hyphenated UUID v4, or configure quantity, case, format, prefix, suffix, and separator in the custom section.
  2. Review the live result and use Copy result when you need to share it.

How the calculation works

The browser supplies 122 random UUID v4 bits. The version nibble is set to 4 and the RFC-compatible variant bits are set correctly; formatting is applied afterward as plain text.

Formula

UUID v4 = secure 128-bit value with version 4 and RFC variant bits

Step-by-step calculation

  1. Use the basic section for one lowercase hyphenated UUID v4, or configure quantity, case, format, prefix, suffix, and separator in the custom section.
  2. The browser supplies 122 random UUID v4 bits. The version nibble is set to 4 and the RFC-compatible variant bits are set correctly; formatting is applied afterward as plain text.
  3. Check the displayed result, then copy it if needed.

Worked example

Generate 10 UUIDs in uppercase braces format, add the prefix record-, and separate the final values with new lines for easy import.

Risk guidance

What is a GUID?

A GUID is a 128-bit identifier used to label records without coordinating one central sequence. GUID is common Microsoft terminology; UUID is the standards-oriented name, and the terms usually refer to the same identifier format.

What UUID version 4 means

UUID v4 identifiers are random-based. Their fixed version and variant bits identify the format, while the remaining 122 bits come from secure browser randomness, making accidental collisions extremely unlikely for ordinary use.

Common GUID and UUID uses

Developers use UUIDs for database rows, API resources, software records, file names, events, and identifiers created across distributed systems.

Formatting and letter case

Standard UUIDs contain five hyphen-separated hexadecimal groups. You can remove hyphens, add braces or parentheses, use the urn:uuid: prefix, and select uppercase or lowercase. Letter case does not change the identifier value.

Local generation and privacy

UUIDs are generated in this browser and are not submitted to a generation service. Prefixes, suffixes, separators, and output are rendered as plain text rather than HTML.

UUIDs are not secrets

A UUID should not automatically be treated as a password, authentication token, encryption key, or other secret. Use security-specific credential and key-generation systems for those purposes.

Frequently asked questions

Is a GUID the same as a UUID?

The terms usually describe the same 128-bit identifier format; GUID is common Microsoft terminology.

Are these GUIDs generated locally?

Yes. Secure browser APIs generate them without sending the values to a server.

Are generated GUIDs unique?

UUID v4 collisions are extremely unlikely, and duplicate values are rejected within each generated batch.

What is UUID version 4?

It is a random-based UUID with fixed version and variant bits and 122 random bits.

Can I remove the hyphens?

Yes. Choose the no-hyphens format, or use braces, parentheses, standard, or URN output.

Can I generate multiple GUIDs?

Yes. The custom generator creates up to 10,000 per batch.

Should I use a GUID as a password or secret?

No. Do not automatically treat UUIDs as passwords, tokens, encryption keys, or other secrets.

Does this tool send my inputs anywhere?

No. The interactive calculation runs in your browser and this site does not submit tool inputs to a backend.

How should I use the result?

Check that the entered units and values match your situation, especially around dates, breaks, and rounding.

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