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UUID / ULID / NanoID

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This tool never uploads your input.

Generate UUID v4, UUID v7, ULID, or NanoID in this tab. v7 and ULID leak creation time by design; v4 and NanoID do not. None of these is a password, and collisions are unlikely — not impossible — at huge scale.

You need fixture ids, a primary key, or a short public slug, and uuidgenerator.net is an ad farm. This page mints UUID v4, UUID v7, ULID, and NanoID in the current tab — that mix is the product, not a single crypto.randomUUID() toy.

It is not password generator.

Which id to pick

Kind Shape Time-ordered Typical use
UUID v4 8-4-4-4-12 hex No Unpredictable public ids
UUID v7 8-4-4-4-12 hex (RFC 9562) Yes New DB primary keys
ULID 26 Crockford chars Yes String-only stores, existing ULID code
NanoID Short URL-safe No Share links, slugs

v7’s timestamp is a feature for indexes and a leak if competitors can read your growth from ids. Postgres and app libraries have been adding v7 since the RFC; confirm your driver before you migrate.

How to use it

  1. Choose v4, v7, ULID, or NanoID.
  2. Set how many to mint. Copy the list.
  3. If you needed a human password, leave this page.

Honest limits

  • Collision resistance is “good enough for normal apps,” not a formal uniqueness service.
  • We do not allocate from a central authority.
  • Not v1, v5, or KSUID.

For hashing a string you already have, use hash generator.

FAQ

Should new database primary keys be v4 or v7?

RFC 9562 (2024) standardized UUID v7: a Unix-ms timestamp plus random bits, so inserts tend to stay sequential in a B-tree. v4 is still right when the ID is public and you do not want the created-at time in the identifier.

What is ULID vs UUID v7?

Both are time-sortable. ULID is a 26-character Crockford base32 string, not an IETF UUID type. Use v7 if you want a native uuid column; use ULID when you already standardized on that string form.

When is NanoID the pick?

Short, URL-safe public ids. It is not a UUID and is not time-ordered. Do not trim it so short that birthday-bound collisions become a product risk.

Are these secret tokens?

v7 and ULID encode time. None of the four is a substitute for a high-entropy session secret from a password generator. Do not treat a UUID as a capability URL unless you understand guessability.

Do you generate UUID v1?

No. v1’s MAC-address history is a privacy footnote we are not reviving.

Is generation uploaded?

No. IDs are minted in this tab.

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