Generate, validate and decode UUID v4, v7, v1, v5 and ULID in your browser, with no server. A UUID you validate goes into the page address so you can share it.
Click Generate to create a new UUID
UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify objects in distributed systems. UUID v4 uses random bits - the collision probability is 1 in 5 undecillion (5 x 10^36) for any two IDs. UUID v1 encodes the current timestamp so the creation time can be extracted later.
ULID (Universally Unique Lexicographically Sortable Identifier) encodes a 48-bit millisecond timestamp plus 80 bits of randomness into a 26-character Crockford Base32 string. ULIDs sort chronologically by default, making them practical as database primary keys where order matters.
All generation runs in your browser using crypto.randomUUID() for v4 and crypto.getRandomValues() for v1 and ULID. Nothing is sent to any server.