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UUID Generator (v4)

Generate random UUID v4 identifiers instantly.

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Free Online UUID Generator — Random v4 & Bulk

Generate cryptographically random UUID v4 identifiers with a single click. UtilHub's UUID Generator produces RFC 4122-compliant universally unique identifiers that you can use for database primary keys, session tokens, tracking IDs, and anywhere you need guaranteed uniqueness without a centralized authority. Generate one at a time or create hundreds in bulk — every UUID is generated directly in your browser using the Web Crypto API.

How to use UUID Generator (v4)

  • Click "Generate UUID" to create a new ID.
  • Adjust the quantity slider for bulk generation.
  • Toggle "Hyphens" to format the output.
  • Click "Copy" to save to clipboard.

Features

  • RFC 4122 compliant — Generates version 4 UUIDs using the Web Crypto API for true randomness, not pseudo-random Math.random().
  • Bulk generation — Generate up to 500 UUIDs at once. Perfect for seeding databases, test data, or migration scripts.
  • Format options — Output with or without hyphens, uppercase or lowercase. Match whatever format your system expects.
  • Zero duplicates — The astronomical keyspace of UUID v4 (2¹²² possibilities) makes collisions virtually impossible.

Frequently Asked Questions

What is a UUID v4 and when should I use it?

A UUID v4 (Universally Unique Identifier, version 4) is a 128-bit identifier generated from random numbers. It looks like <code>550e8400-e29b-41d4-a716-446655440000</code>. Use UUID v4 whenever you need a unique ID without coordinating with a central database — common use cases include database primary keys, API request IDs, file names, and distributed system identifiers.

Are the UUIDs generated here truly random and secure?

Yes. This tool uses the Web Crypto API (<code>crypto.getRandomValues()</code>), which provides cryptographically strong random numbers from your operating system's entropy pool. This is far more secure than <code>Math.random()</code>, which many online UUID generators still use.