🆔 UUID Generator
Generate UUID v4 (random), v1 (timestamp), or v7 (sortable) instantly. Bulk generate up to 100 at once. Everything runs in your browser — nothing is sent to any server.
FAQ
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hexadecimal digits in 5 groups separated by hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000). UUIDs are used as database primary keys, session tokens, correlation IDs, and file names when uniqueness is required without a central authority.
What is the difference between v1, v4, and v7?
v1 embeds the current timestamp and a node ID (usually a random value simulating a MAC address). It is time-ordered but exposes timestamp information. v4 is entirely random (122 random bits via crypto.getRandomValues()) — the safest choice for general use. v7 places a Unix millisecond timestamp in the high bits, making UUIDs lexicographically sortable — ideal for database primary keys where index performance matters.
Are these UUIDs safe to use in production?
Yes. v4 and v7 use crypto.randomUUID() or crypto.getRandomValues(), which are cryptographically secure browser APIs. The probability of two v4 UUIDs colliding is approximately 1 in 5.3×10³⁶.
Is my data sent to a server?
No. All UUID generation happens locally in your browser using the Web Crypto API. Nothing is ever transmitted.
When should I use UUID v7 instead of v4?
Use v7 when you store UUIDs in a database and want efficient B-tree indexing. Because v7 UUIDs are time-sorted, they insert at the end of an index rather than in random positions, reducing page splits and improving INSERT performance.