UUID v4 Generator

Generate UUIDs, ULIDs, and NanoIDs instantly in your browser — no server, no tracking.

No sign-up. No tracking. Runs in your browser.

Random, 128-bit, RFC 4122. Most widely used.

When to use which type

UUID v4

Purely random (RFC 4122). The most widely supported unique identifier format. Use when you need a standard UUID and sorting by creation time does not matter.

UUID v7

Time-ordered UUID (RFC 9562). The first 48 bits encode a millisecond timestamp, making IDs lexicographically sortable. Prefer over v4 for database primary keys — better index locality, fewer B-tree page splits.

ULID

26-character Crockford Base32 string: 10 chars timestamp + 16 chars randomness. Lexicographically sortable and URL-safe. A compact drop-in for UUID when a shorter, human-readable identifier is preferred.

NanoID

Configurable length and alphabet. Best for short tokens, session IDs, and slugs. The default 21-character length has the same collision probability as UUID v4.

Common Use Cases

  1. Generate UUIDs for database seedsGenerate up to 100 UUID v4 identifiers in one click for use as primary keys in database seed scripts or test fixtures.
  2. Compare ID formats for a new projectGenerate UUID v4, UUID v7, ULID, and NanoID side-by-side to compare their formats, sortability, and length before choosing an ID strategy for a new service.

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