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UUID Generator

Generate cryptographically secure UUIDs in multiple versions. Generate one or many at once and copy to clipboard.

UUID v4 - Randomly generated using cryptographically secure random bytes. The most widely used UUID version. No information about when or where it was generated is embedded.

About UUID Generator

A UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify objects in computer systems. This tool generates UUIDs using your browser's crypto.getRandomValues() API - the same cryptographic source used by operating systems - so every UUID is truly random and unpredictable.

UUID Versions

  • v4 - 122 bits of randomness. No embedded metadata. The most common choice for database IDs, session tokens, and API keys.
  • v1 - Encodes the current timestamp and a node identifier. Monotonically increasing within a millisecond.
  • v7 - Newer standard (RFC 9562). Timestamp-ordered random UUID - ideal for database primary keys as it sorts chronologically.
  • v5 - Deterministic: given the same namespace and name, always produces the same UUID. Uses SHA-1 hashing.

How to Use

  1. Choose the UUID Version: v4 (random) is most common for general use.
  2. Set Count to generate multiple UUIDs at once (1–100).
  3. Toggle Uppercase if your system requires uppercase hex.
  4. Click Generate - the UUIDs appear instantly.
  5. Click any UUID or Copy All to copy them.

How It Works

UUID v4 is generated using crypto.randomUUID() (modern browsers) or crypto.getRandomValues() with RFC 4122 bit-setting for version and variant fields. The result is formatted as 8-4-4-4-12 hex groups separated by hyphens.

Example

Generate a UUID for a new database record: 550e8400-e29b-41d4-a716-446655440000. Use it as a primary key, correlation ID, or idempotency key in your API. Statistically, the probability of collision across trillions of UUIDs is negligible.

FAQ

Theoretically yes, but practically impossible. A UUID v4 has 2¹²² possible values (~5.3 × 10³⁶). The probability of generating a duplicate in 1 billion UUIDs per second for 100 years is still negligible.
GUID (Globally Unique Identifier) is Microsoft's name for the same concept. They are technically identical - a GUID is a UUID. The terms are interchangeable.
Yes. UUID v4 and v7 generation uses crypto.getRandomValues(), which is the browser's CSPRNG (cryptographically secure pseudo-random number generator).