UUID / ULID Generator

Pick a format with the tabs — UUID v4, UUID v7, or ULID. Set how many to generate at once. IDs appear immediately; hit Regenerate for a new batch.

Toggle uppercase, hyphens, or braces to match your target system's convention. Copy all with one click, or download as a text file.

Two shortcuts:

UUID v4 — the default when you want a random ID with no coordination. Distributed systems, session tokens, request IDs, one-off things where order doesn't matter.

UUID v7 — when the ID becomes a database primary key. The first 48 bits are a timestamp, so B-tree indexes stay compact. Same 128 bits as v4, same collision-safe randomness, but sortable.

ULID — when you want v7's time-ordering but shorter (26 chars vs 36) and URL-safe (no hyphens, Crockford base-32 skips ambiguous characters like 0/O).

Count — 1, 10, 100, or 1000 IDs per batch.

Uppercase — ABC-123 vs abc-123. ULIDs default to uppercase; UUIDs default to lowercase per RFC 4122.

Hyphens (UUID only) — with hyphens (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx) or without.

Braces — wraps each ID in { }. Standard in some Microsoft contexts.

Not all databases support UUID v7 natively. Postgres, MySQL, SQLite can store it as text or bytea; some ORMs may not parse the version bits correctly. Test before you commit to it as a primary key type.

ULID lexicographic order. ULIDs sort correctly as strings — that's the whole point. UUID v7 requires binary sort for correct ordering; string sort mostly works because the hex is right-padded per byte, but be aware.

Collision risk is essentially zero. Both UUID v4 (122 bits of randomness) and ULID (80 bits of randomness within one ms) have negligible collision probability at real-world scale.

Uses cryptographic randomness. crypto.randomUUID() and crypto.getRandomValues() under the hood — safe for tokens and IDs where guessability matters. Not Math.random().

Everything runs in your browser. No server involved. IDs are generated by your browser's cryptographic random number generator.