UUID generator

A UUID is a 128-bit value any machine can mint locally with effectively zero risk of colliding with one minted by another. This generator emits two of the eight versions defined by RFC 9562. UUID v4is fully random — 122 bits of entropy — and is what most code, libraries, and APIs mean when they say “UUID.” Reach for it when you need an opaque, unguessable identifier. UUID v7 embeds a millisecond Unix timestamp in its first 48 bits, so v7 IDs sort lexicographically in creation order. That property matters when UUIDs are primary keys in a B-tree index: v4 keys fragment the index on insert; v7 keys append cleanly.

Use the bulk field to mint up to 100 IDs at once for seeding fixtures, generating filenames, or populating an idempotency-key list. The optional prefix prepends a short tag (e.g. user_) so the IDs are self-describing in logs. Generation happens locally — no values leave your browser. Read the full explainer for each version's bit layout, when v7 is the right pick, and the history behind both.