What is a UUID?
A UUID is a 128-bit identifier commonly used for database records, files and other objects. RFC 9562 defines the current UUID formats, including versions 4 and 7.
UUID v4 is random-based. This generator uses the browser's cryptographic randomness API, but the result is still an identifier rather than a password, secret or authentication token.
UUID v7 and time ordering
UUID v7 combines a Unix millisecond timestamp with random data. Its timestamp prefix provides useful time ordering, so v7 can suit records that benefit from roughly chronological identifiers. UUID v4 remains useful when time ordering is not needed.
The inspector can expose the embedded v7 timestamp. That value does not independently prove when a database record or real-world event was created.
Generate UUID batches
Choose UUID v4 or v7 and generate up to 100 identifiers at once. You can copy an individual UUID or copy the full batch as newline-separated text.
Validate and inspect a UUID
The inspector validates canonical UUID syntax, identifies the encoded version and variant, and normalises valid uppercase input. For UUID v7, it also displays the embedded timestamp in UTC and Unix milliseconds.
Syntax, version and variant inspection do not authenticate a UUID, prove its source or show that it was generated securely.
UUIDs stay in your browser
UUIDs are generated and checked in your browser. They are not sent to UtiliBits or added to the page URL.
Frequently asked questions
What is a UUID?
A UUID is a 128-bit identifier written in a standard hexadecimal format. It is commonly used to identify records and objects without relying on one central numbering system.
What is the difference between UUID v4 and UUID v7?
UUID v4 is random-based. UUID v7 combines a Unix millisecond timestamp with random data, which gives UUIDs useful time ordering.
Are UUIDs generated securely?
This tool uses the browser cryptographic randomness API when generating UUID v4 and the random portion of UUID v7. A UUID is still an identifier, not a password, secret or authentication token.
Can I generate multiple UUIDs?
Yes. You can generate up to 100 UUIDs at once, then copy one UUID or the full batch.
Can I validate an existing UUID?
Yes. The inspector checks canonical UUID syntax, identifies the encoded version and variant, and normalises valid uppercase input. These checks do not authenticate the UUID or prove its source.
What timestamp is stored in UUID v7?
UUID v7 stores a Unix timestamp in milliseconds. The inspector can display it, but the timestamp alone does not prove when a database record or real-world event was created.
Can a UUID be used as a password or secret?
No. UUIDs are identifiers and should not be treated as passwords, secrets or authentication tokens.
Are UUIDs sent to UtiliBits?
No. UUIDs are generated and checked in your browser and are not sent to UtiliBits.