OmniTools360*

UUID v4 Generator

generatorsAIR-GAPPED

Generate batch RFC4122-compliant Universally Unique Identifiers (UUIDs) v4 in seconds.

Generated UUIDs:

About UUID v4 Generator

The OmniTools360 UUID Generator creates version 4 UUIDs (random unique identifiers) in bulk, from 1 to 100 at a time. You can output them in uppercase or without hyphens. Copy the full list with one click for databases, tests, or code.

How does the UUID v4 Generator work?

The tool fills the standard UUID v4 template with random hexadecimal digits, sets the version digit to 4, and sets the variant digit to 8, 9, a, or b. It uses the browser's Math.random function, which is fine for test data and general IDs.

Explanation

A UUID is a 128-bit identifier written as 32 hex digits in the pattern 8-4-4-4-12, for example xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. In version 4, the "4" marks the version and "y" is 8, 9, a, or b to mark the variant. The other 122 bits are random, giving about 5.3 × 10^36 possible values.

How to use the UUID v4 Generator

1

Enter how many you need in Number of UUIDs (1 - 100).

2

Turn on UPPERCASE or Remove Hyphens if you need those formats.

3

Click Regenerate for a new list.

4

Click Copy All to copy every UUID, one per line.

UUID v4 Generator examples

Standard format
A typical result looks like 3f2b8c1e-9a4d-4e7b-b2c5-1d6f8a9e0c47 (36 characters with hyphens).
Remove Hyphens
The same style becomes 3f2b8c1e9a4d4e7bb2c51d6f8a9e0c47 (32 characters).
UPPERCASE
3F2B8C1E-9A4D-4E7B-B2C5-1D6F8A9E0C47, useful for systems that expect capital letters.

Frequently Asked Questions about UUID v4 Generator

What is a UUID v4?

A UUID v4 is a 128-bit identifier made mostly of random numbers. It is written as 32 hexadecimal digits in five groups, like 8-4-4-4-12. The third group always starts with 4 to show the version. Because 122 bits are random, two UUID v4 values are extremely unlikely to match.

Can two UUIDs ever be the same?

In theory two UUIDs can be the same, but with good randomness the chance is extremely small. There are about 5.3 × 10^36 possible v4 values. You would need to create around 2.7 × 10^18 UUIDs to reach a 50% chance of one duplicate. For almost all projects, duplicates are not a practical worry.

What is the difference between a UUID and a GUID?

A UUID and a GUID are basically the same thing. GUID (Globally Unique Identifier) is the name Microsoft uses, while UUID (Universally Unique Identifier) is the name in the official standard, RFC 9562. Both are 128-bit values written in the same 8-4-4-4-12 hexadecimal format.

Should I use UUIDs as database primary keys?

UUIDs work well as primary keys when records are created in many places or IDs must not be guessable in order. The downsides are larger size than integers and slower indexing, because random v4 values are not sorted. Time-ordered UUID v7 is often a better choice for database keys.

Are UUIDs secure enough to use as secret tokens?

UUIDs are not meant to be secret tokens. They are designed to be unique, not unguessable. This tool uses Math.random, which is not cryptographically secure, so do not use its output for passwords, session tokens, or reset links. For secrets, use a generator built on a cryptographically secure random source.