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Utilnivo

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Utilnivo

UUID v4 Generator

Generate random UUID v4 identifiers for databases and APIs.

No registration
  • On your device

Browse more in Developer or all tools.

What is a UUID generator?

A UUID generator creates random unique identifiers (v4) for databases, APIs, and test data. IDs are generated locally in your browser.

Private on your device

Your information stays on your device and is not uploaded.

Related tools

This UUID v4 generator creates RFC 4122 version 4 random identifiers. Generate one or many UUIDs for database keys, correlation IDs, and test fixtures—using cryptographic randomness on your device.

Version 4 UUIDs are random—collision probability is negligible for practical app scales.

Use UUID v7 or ULID when sortable time-ordered IDs matter for database indexing.

How to use this tool

Click generate, copy the UUID, or bulk-generate multiple values for test datasets.

Worked example

Example: generate `550e8400-e29b-41d4-a716-446655440000`-style IDs for seeding a local Postgres table without collisions.

When to use this

  • Seeding development databases.
  • Creating correlation IDs for distributed tracing examples.
  • Generating primary keys in prototypes.

Common examples

  • Generate v4 UUID for a new database primary key in local seed scripts.
  • Batch of five UUIDs for mock API fixtures in integration tests.
  • UUID for trace id in log correlation examples in documentation.
  • Ten UUID v4 values → seed rows for local integration test database.
  • UUID v7 batch → ordered IDs for event-sourcing demo data.

Common mistakes

  • Using UUID v4 when sequential IDs would index better.
  • Hardcoding generated UUIDs in production migrations without coordination.
  • Expecting v4 to embed timestamp—it does not.

How it works

Generates UUID v4 (random) or v7 (time-ordered) identifiers using crypto-random bytes on your device. Supports bulk generation with optional uppercase and hyphen formatting.

Limitations

Results are based on the inputs you provide and may not cover every edge case. This tool is for general use and is not professional advice.

Privacy and file handling

Your data stays on your device and is not uploaded.

Related UUID Generator pages

These pages use the same uuid generator with examples tailored to different tasks.

FAQ

Frequently asked questions

What is UUID v4?

Version 4 UUIDs are 128-bit random identifiers with standard formatting (8-4-4-4-12 hex groups).

Are UUIDs guaranteed unique?

Practically unique through randomness—not mathematically impossible to collide, but extremely unlikely.

Uppercase or lowercase?

Both are valid. APIs often accept either; stay consistent within a project.

Related pages

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