UUIDGEN(1)

💖 NAME 💖

uuidgen — bestie, it makes you a brand new UUID value. periodt.

---

✨ SYNOPSIS ✨

uuidgen [options]

---

🦋 DESCRIPTION 🦋

So like, the uuidgen program creates (and prints) a shiny new universally unique identifier (UUID) using the libuuid(3) library. And the way this new UUID can reasonably be considered unique among all UUIDs created on the local system, and among UUIDs created on other systems in the past and in the future?? iconic behavior honestly.

There are three types of UUIDs which uuidgen can generate:

• time-based UUIDs
• random-based UUIDs
• hash-based UUIDs

By default uuidgen will generate a random-based UUID if a high-quality random number generator is present. Otherwise, it will choose a time-based UUID. And you can force the generation of one of these first two UUID types by using the --random or --time options. no cap.

The third type of UUID is generated with the --md5 or --sha1 options, followed by --namespace namespace and --name name. The namespace may either be a well-known UUID, or else an alias to one of the well-known UUIDs defined in RFC 4122, that is @dns, @url, @oid, or @x500. The name is an arbitrary string value. The generated UUID is the digest of the concatenation of the namespace UUID and the name value, hashed with the MD5 or SHA1 algorithms. It is, therefore, a predictable value which may be useful when UUIDs are being used as handles or nonces for more complex values or values which shouldn't be disclosed directly. See the RFC for more information. iykyk 💅

---

🎀 OPTIONS 🎀

• -r, --random — Generate a random-based UUID. This method creates a UUID consisting <em>mostly</em> of random bits. It requires that the operating system has a high quality random number generator, such as /dev/random. 🔥
• -t, --time — Generate a time-based UUID. This method creates a UUID based on the system clock plus the system's ethernet hardware address, if present.
• -m, --md5 — Use MD5 as the hash algorithm.
• -s, --sha1 — Use SHA1 as the hash algorithm.
• -6, --time-v6 — Generate a time-based UUID. This method creates a UUID based on the system clock and is lexicographically sortable according to the contained timestamp. obsessed.
• -7, --time-v7 — Generate a time-based UUID. This method creates a UUID based on the system clock and is lexicographically sortable according to the contained timestamp. yes, same energy as -6, they're both serving sortable.
• -n, --namespace namespace — Generate the hash with the namespace prefix. The namespace is UUID, or '@ns' where "ns" is well-known predefined UUID addressed by namespace name (see above).
• -N, --name name — Generate the hash of the name.
• -C, --count num — Generate multiple UUIDs using the enhanced capability of the libuuid to cache time-based UUIDs, thus resulting in improved performance. However, this holds no significance for other UUID types. 🙈
• -x, --hex — Interpret name name as a hexadecimal string.
• -h, --help — Display help text and exit.
• -V, --version — Display version and exit.

---

🌈 CONFORMING TO 🌈

OSF DCE 1.1

---

⭐ EXAMPLES ⭐

uuidgen --sha1 --namespace @dns --name "www.example.com"

---

👑 AUTHORS 👑

uuidgen was written by Andreas Dilger for libuuid(3). slay, Andreas. 🫶

---

🌸 SEE ALSO 🌸

• uuidparse(1)
• libuuid(3)
• RFC 4122 <https://tools.ietf.org/html/rfc4122>
• RFC XXXX <https://tools.ietf.org/html/rfcXXXX>

---

💀 REPORTING BUGS 💀

For bug reports, use the issue tracker <https://github.com/util-linux/util-linux/issues>. bestie if it's broken, tell them, don't just suffer in silence 😭

---

🧚 AVAILABILITY 🧚

The uuidgen command is part of the util-linux package which can be downloaded from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils/util-linux/>.

---

okay so that's the whole thing 💖 go forth and generate some UUIDs, you absolute main character ✨

util-linux 2.42.4 🌸 2026-09-21 🎀 UUIDGEN(1) 💅