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Utilnivo

Developer

Utilnivo

UUID Generator

Generate UUIDs for apps, tests, and databases.

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

Create UUID version 4 (random) or version 7 (time-ordered) identifiers on your device. Generate one or many at once, with optional uppercase and hyphen formatting. UUIDs are never stored.

UUID v4 is random; UUID v7 is time-ordered and can be friendlier for database indexes. Use v4 for opaque identifiers and v7 when sortable creation order helps logging or storage layout.

UUIDs generated here are suitable for development fixtures and correlation IDs. For security-sensitive session tokens, follow your platform's recommended token format and entropy requirements.

Copy without braces when your database column expects the canonical hyphenated string format only.

Collision risk with random UUID v4 is negligible for practical apps, but databases still need unique constraints—never rely on probability alone for financial ledger keys.

Nil UUID (`00000000-0000-0000-0000-000000000000`) is valid in some APIs as a sentinel—do not use it when you need a globally unique new record.

PostgreSQL `gen_random_uuid()` and this generator both produce RFC-compliant strings—pick one source per table and stay consistent.

Bulk-generate ten IDs when seeding fixtures, but use database defaults in production migrations to avoid check-in of live identifiers.

How to use this tool

1. Select UUID version v4 or v7. 2. Enter how many IDs to generate. 3. Choose uppercase and hyphen options if needed. 4. Click Generate UUIDs. 5. Copy one ID or all from the results area.

Worked example

Example: generate one UUID v4 with hyphens and lowercase—typical output looks like 550e8400-e29b-41d4-a716-446655440000 (yours will differ).

When to use this

  • Seeding database primary keys in local development.
  • Creating trace IDs for log correlation examples.
  • Generating mock API fixture identifiers.
  • Quick unique IDs for test documents or filenames.

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 v4 UUIDs where sequential IDs are required for sorting.
  • Assuming UUIDs are guaranteed unique across distributed systems without version choice.
  • Pasting UUIDs with wrong hyphen grouping into strict validators.
  • Using UUID as a security token—it is an identifier, not a secret.

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 workflows

Explore focused guides that reuse this uuid generator with different examples and FAQs.

FAQ

Frequently asked questions

What is the difference between UUID v4 and v7?

Version 4 UUIDs are fully random. Version 7 UUIDs start with a Unix timestamp in milliseconds, so they sort roughly by creation time while still including random bits.

How is randomness generated?

The generator uses the secure random generation for strong randomness.

Are generated UUIDs stored?

No. UUIDs are generated on your device and are not logged or sent to a server.

What is this tool?

Generates random UUID v4 identifiers for databases, APIs, and test fixtures.

Is formatting done locally?

Yes. UUIDs are generated in your browser and are not uploaded.

Is it free?

Yes. Free with no signup.

Which related tools should I use next?

Try UUID Lookup, Hash Generator, or Password Generator.

Part of these workflows

This tool is one step in a longer job. Jump straight to your step or open the full workflow guide.

Related pages

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