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UUID & ULID Generator.

Random UUID v4, time-ordered UUID v7, or ULIDs, generated in batches with cryptographically strong randomness. Pick a count, copy one or copy all. Every value is made locally in your browser.

// v4 vs v7 vs ULID: which one?
  • UUID v4: 122 bits of pure randomness. Collisions are astronomically unlikely. Downside: the values are unordered, which can fragment a database B-tree index when used as a primary key.
  • UUID v7: a millisecond timestamp in the high bits, random in the rest. Sorts in roughly creation order while staying globally unique. The modern default for database keys.
  • ULID: 26-character Crockford base32. Also time-sortable, slightly more compact, and friendlier in URLs (no hyphens, case-insensitive, avoids ambiguous characters).

Randomness: every value uses crypto.getRandomValues(), the browser's cryptographically secure RNG, not Math.random(). Generation happens entirely on your device.

Related: need a secret instead of an identifier? The Strong Password Generator uses the same secure RNG.

// a free, browser-only tool by Tiempo Software, built in Omaha, Nebraska. Runs entirely in your browser; nothing you enter is uploaded. see all tools.