Developer tool

UUID & ULID Generator Online

Generate UUID v4, v1, v5 or ULID identifiers in batches and choose output formatting for your workflow.

Type:

Format:

UPPERCASE Hyphens (8-4-4-4-12)

Generated Identifiers 0 generated

Total Quantity 0

Identifier Type UUID v4

Length Per ID 36 chars

Collision Risk Near Zero (2^122)

Namespace Domain / URL: Name / Key:

How to use this tool

Select the identifier type and set the batch size.
For UUID v5, provide the namespace and name required by your application.
Generate and copy the identifiers, then enforce uniqueness where you store them.

Example and use case

A UUID has a representation such as 550e8400-e29b-41d4-a716-446655440000. This is a format example, not a new identifier to reuse.

Limitations to check

IDs are not passwords or authorization tokens. Time-based identifiers can reveal creation order or time. Identical UUID v5 namespace/name inputs deliberately produce the same ID; applications still need unique constraints.

Processing and privacy

The tool's browser code handles entered text or selected files locally. Optional URL imports and external resources can make network requests. This website also uses third-party scripts, including analytics and advertising. Read the privacy policy and use sample data when testing sensitive workflows.

Found a problem? Report a tool issue with the browser version and steps to reproduce it. Avoid sending private document content or credentials.

Frequently asked questions

Which UUID type should I choose?

Choose based on your application's requirements. v4 is random, v1 is time-based, and v5 is deterministic from a namespace and name.

Is a UUID safe as a password?

Do not treat an identifier as a secret. Use a dedicated secure token or password generation workflow.

Why does UUID v5 repeat?

The same namespace and name intentionally produce the same v5 UUID. Change the input when you need another deterministic identifier.