Free · No signup · No install
UUID Generator
Generate random v4, sortable v7 or name-based v5 UUIDs and GUIDs instantly, right in your browser.
Generated locally with the Web Crypto API — nothing leaves your browser.
What Is a UUID?
A UUID is a 128-bit identifier written as 32 hex characters in the 8-4-4-4-12 pattern, for example 550e8400-e29b-41d4-a716-446655440000, so that independent systems can create identifiers that never clash. The format dates back to Apollo Computer's Network Computing System in the late 1980s, was standardised as RFC 4122 in 1998, and was modernised by RFC 9562 in 2024; Microsoft calls the identical structure a GUID.
How to Use a UUID?
Creating a UUID takes a single line of code in almost every language — crypto.randomUUID() in the browser, uuid.uuid4() in Python, UUID.randomUUID() in Java — so in practice how to use a UUID comes down to knowing where to put one and which version to pick. Generate a value wherever you need a unique key, then store or send the 36-character string as ordinary text: it drops into a database column, an API response, a filename or a URL query parameter with no encoding. Use random v4 for everyday identifiers, time-ordered v7 when the value will live in an indexed table and you want inserts to stay sequential, and name-based v5 when the same input must always produce the same identifier. Need a few thousand at once? Produce them with the bulk generator and download the list as CSV. And if a UUID arrives from somewhere else and you are not sure it is well formed, check it with the UUID validator before you store it.
What Is the UUID Generator?
The UUID generator on this page produces valid identifiers on demand. It runs entirely in your browser using the Web Crypto API, so every value is created on your device and never uploaded to a server. All the standard versions are supported — random v4, time-ordered v7 and v6, name-based v5 and v3, plus the legacy v1 and the custom v8 — together with formatting options for uppercase letters, no hyphens or surrounding braces. Beyond a single value it handles batches of up to 10,000 at once, validates and reformats UUIDs you already have, and exports everything as plain text or CSV. Because nothing leaves the page, it keeps working offline once it has loaded.
How to Use the UUID Generator?
- Choose a version in the Version menu — it starts on v4, the everyday default. The value is produced as soon as you pick: there is no submit step, and changing the version, the namespace or any format toggle regenerates the result instantly.
- For name-based v3 or v5, type your input into the Name field (a domain, a URL, any string) and press Generate. That input is what makes the result reproducible.
- Set how many you need, then copy the whole list or download it as .txt or .csv.
One example worth trying: switch to v5, set the namespace to DNS and type www.example.com. The generator returns 2ed6657d-e927-568b-95e1-2665a8aea6a2 — and so does every other v5 generator, on every machine, forever, because a v5 UUID is simply the SHA-1 hash of the namespace plus the name. That is what makes v5 values good durable keys for domains, URLs and anything else that already has a stable identity.