tofo-boxtools

UUID Generator

developer

Generate UUID v4, v1-style, and nil UUIDs instantly. Bulk generation, uppercase/lowercase, and no-hyphen formats supported.

uuid generatorgenerate uuid onlineuuid v4 generatorrandom uuid generatorguid generator onlineuuid generator free
276f271d-d9d6-449d-a740-afa7917299f1
1
1102550

UUID v4 · RFC 4122 · Generated in browser · Never sent to server

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What is UUID Generator?

UUID Generator is a free online developer utility. Generate UUID v4, v1-style, and nil UUIDs instantly. Bulk generation, uppercase/lowercase, and no-hyphen formats supported. It runs entirely in your browser, making it fast and accessible without any setup or installation.

How to Use UUID Generator

  1. 1

    Select your preferred format: Standard (lowercase with hyphens), Uppercase, No hyphens, or Nil UUID.

  2. 2

    Use the Count slider to generate 1 to 50 UUIDs at once.

  3. 3

    Click Generate UUID to create new identifiers.

  4. 4

    Click Copy next to any UUID to copy it, or use Copy All to copy the entire list.

Common Use Cases

  • →Generating unique IDs for database records in development.
  • →Creating correlation IDs for distributed system logging.
  • →Generating unique filenames to avoid collisions in storage systems.
  • →Creating test data with unique identifiers for automated tests.

Frequently Asked Questions

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit identifier standardized by RFC 4122. It is designed to be unique across all space and time without requiring a central authority to coordinate generation. UUIDs are used as database primary keys, session IDs, and correlation IDs.

What is UUID v4?

UUID v4 is randomly generated using a cryptographically secure random number generator. It has 122 bits of randomness, making collisions astronomically unlikely. It is the most commonly used UUID version for general-purpose unique identifiers.

What is a Nil UUID?

A Nil UUID is a special UUID where all bits are set to zero: 00000000-0000-0000-0000-000000000000. It is used as a null or default value in systems that require a UUID type but need to represent 'no value'.

Are generated UUIDs truly unique?

UUID v4 has 2^122 possible values (approximately 5.3 × 10^36). The probability of generating two identical UUIDs is so small it is considered impossible in practice — you would need to generate billions of UUIDs per second for billions of years to have a meaningful collision probability.

🖼️
Image Tool

Try Image Compressor

Reduce image size up to 80% — free, instant, no upload needed.

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🖼️
Image Tool

Try Image Compressor

Reduce image size up to 80% — free, instant, no upload needed.

→