UUID Generator

UUID Generator — Create Random UUID v4 Values Online

A UUID Generator creates unique identifiers that can be used in databases, APIs, distributed systems, test data, and application records. UUID stands for Universally Unique Identifier. The most common format is a 36-character string with hexadecimal digits and hyphens, such as 550e8400-e29b-41d4-a716-446655440000.

The most popular variant for general use is UUID v4, which is generated from random values. Because the randomness space is extremely large, the chance of two properly generated UUID v4 values colliding is practically negligible for normal applications. That is why developers often use UUIDs when they need identifiers that can be generated independently across different systems without a central counter.

There are several UUID versions, each designed for a different purpose. Historically, the most widely known are v1 (time-based), v3 (name-based with MD5), v4 (random), and v5 (name-based with SHA-1). Newer standards also define v6, v7, and v8 for improved ordering and custom use cases. So if someone asks “how many UUID versions are there,” the modern answer is that multiple versions exist, with v1 through v8 defined across RFCs, although not all are equally common in everyday tools.

How to Use

1. Open the UUID generator tool. 2. Choose how many UUIDs you want to create, if the tool supports batch generation. 3. Generate the result. In most cases, the default output is UUID v4. 4. Copy the generated UUID and paste it into your database, config, code, or test data. 5. If your workflow requires ordered or deterministic UUIDs, verify whether you need another version instead of v4.

Examples

• Single UUID v4

Output: c1f4d2c8-7a6b-4b7f-9d2a-5a8e4c1f9b30

• Batch generation

Output:

• 8b9e1a55-9f3f-4c5d-a51b-5c7f6d8a1234
• d7ac3b1e-7e82-4b0c-8d9f-2a45e6c7f891
• 4c9f8a2d-1357-4f8c-b62e-9e0ab123cd45

• Version check

In a UUID like c1f4d2c8-7a6b-4b7f-9d2a-5a8e4c1f9b30, the 4 at the start of the third group indicates that it is version 4.

Tips

• Use UUID v4 when you need random, decentralized identifiers with an extremely low collision risk.
• If you need sortable identifiers, consider whether UUID v7 may fit your system better.
• Do not treat a UUID as a secret. It is an identifier, not an authentication token.
• Keep the original lowercase format unless your system requires uppercase.
• Validate UUID input when accepting values from users or external APIs.

FAQ

What is UUID v4?

UUID v4 is a randomly generated UUID. It uses random bits, with a few reserved bits marking the version and variant.

How many UUID versions are there?

Commonly discussed versions include v1, v3, v4, and v5, while newer specifications also define v6, v7, and v8. In modern standards, UUID versions 1 through 8 exist, though not every tool supports all of them.

Are UUIDs guaranteed to be unique?

Not mathematically guaranteed, but for properly generated UUID v4 values, collisions are so unlikely that they are considered safe for most real-world systems.

When should I not use UUID v4?

If you need sequential ordering, time-based sorting, or deterministic generation from a namespace and name, another version may be more appropriate.

Can I use a UUID as a password or API secret?

No. A UUID is meant for identification, not for secure authentication or secret storage.