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UUID v4 Generator

Used by developers, writers, and creators worldwide.

A UUID v4 generator produces random, RFC 4122-compliant version 4 universally unique identifiers — the 36-character strings developers use as primary keys, request IDs, and identifiers that must never collide. Version 4 UUIDs are built almost entirely from random bits, with the version and variant fields set correctly, so the odds of two ever clashing are vanishingly small. This tool generates properly formatted UUIDs you can drop straight into seed data, test fixtures, configuration, or API requests. Choose how many you need and copy them in one click. It is ideal for seeding databases, writing tests, building mock payloads, and any task that needs valid, throwaway identifiers. Because these are generated client-side from your browser's randomness, they are perfect for development and testing, though for security-critical identifiers you should generate them from a cryptographically secure source in your own runtime rather than copying throwaway values.

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How to use

  1. Choose your options above
  2. Click Generate
  3. Copy your result

Detailed instructions

  1. Choose how many UUIDs you want.
  2. Click Generate to produce version 4 UUIDs.
  3. Copy them into your code or data.
  4. Generate more whenever you need them.

Use Cases

  • •Seeding a database with primary keys
  • •Generating IDs for test fixtures
  • •Building mock API payloads
  • •Creating request or correlation IDs
  • •Filling identifier fields in sample data

Tips

  • →Use them freely for tests and seed data.
  • →Generate production IDs in your own runtime.
  • →They never need central coordination.
  • →Copy a batch at once to save time.

FAQ

what is a version 4 UUID

A version 4 UUID is a 128-bit identifier built mostly from random bits, with fixed version and variant markers. It is the most common UUID type because it needs no central coordination — you just generate one and the chance of a collision is negligible.

are these UUIDs guaranteed unique

Not guaranteed, but the probability of a collision is so small it is effectively zero for normal use. With 122 random bits, you would need to generate an astronomical number before a clash became likely, which is why v4 UUIDs are trusted as keys.

can i use these in production

They are ideal for development, testing, and mock data. For production identifiers — especially anything security-sensitive — generate UUIDs from a cryptographically secure random source in your own application rather than reusing throwaway values copied from a tool.