UUID (Universally Unique Identifier) is a 128-bit label standardized by RFC 4122. Version 4 (random) is the most common; each generated UUID has a collision probability so low it's considered unique for all practical purposes.

A ULID (Universally Unique Lexicographically Sortable Identifier) encodes a millisecond timestamp in the first 48 bits, making ULIDs sortable by creation time. Useful as database primary keys when you want both uniqueness and sort order.

When should I use UUID v7 instead of v4?

UUID v7 includes a timestamp component, making them naturally sortable like ULIDs. Use v7 when your IDs need to be ordered by creation time — such as database primary keys.

Is WebCrypto-generated UUID truly random?

Yes. The browser's crypto.getRandomValues() provides cryptographically secure pseudorandom numbers, making WebCrypto UUIDs suitable even for security-sensitive applications.

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UUID / ULID Generator

Generate UUID v4, UUID v7, ULIDs, and Nano IDs — bulk generation with one click.

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About this tool

Generate universally unique identifiers in multiple formats: RFC 4122 UUID v4 (random), UUID v7 (time-ordered), ULID (Universally Unique Lexicographically Sortable Identifier), and Nano ID. Bulk generation up to 100 at once. All generation uses the cryptographically secure WebCrypto API.

How to use

1 Select the ID format: UUID v4, UUID v7, ULID, or Nano ID.
2 Set the count (1 to 100).
3 Click Generate — all IDs appear in the output box.
4 Click Copy All to copy all generated IDs.

Frequently Asked Questions

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