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UUID App

Free UUID generator for every version

Make a UUID v4, v7, v5 or any other version in one click. Also GUID, Nano ID and ULID. Need thousands? Every generator can export to CSV, JSON or SQL.

Generate a UUID v4Help me choose a version

UUID generators

Each version has its own page with a generator, bulk export and a plain-English explainer.

Free UUID generator: v4, v7, GUID and more

Other ID generators

Not UUIDs, but sometimes the better fit.

Which UUID version should I use?

Find what you need, then use the ID next to it. Not sure? Pick UUID v4.

  • I just need a unique IDUUID v4
  • IDs for a big database tableUUID v7
  • The same ID every time for the same nameUUID v5
  • A short ID for linksNano ID
  • Windows, .NET or the registryGUID

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit ID used to name things in software: database rows, files, orders, users and messages. Any computer can make one on its own, without asking a central server, and it will not clash with IDs made anywhere else.

It is written as 32 letters and numbers in five groups, like this:

3f2b8c1e-9a4d-4e7b-b1c2-5d6e7f8a9b0c
The group sizes are always 8-4-4-4-12. The green digit tells you the version. Theorange digit marks the standard layout.

UUIDs are defined in RFC 9562, the 2024 standard that added versions 6, 7 and 8. A GUID is the same thing under Microsoft's name.

All UUID versions at a glance

VersionMade fromSorts by timeBest for
v1Time + device IDNoOlder systems
v3MD5 of a nameNoOld name-based IDs
v4RandomNoAlmost everything
v5SHA-1 of a nameNoRepeatable IDs
v6Time + device IDYesUpgrading from v1
v7Unix time + randomYesDatabase keys
v8Your own layoutDependsCustom needs

Version 2 exists but is almost never used, so we leave it out.

Why use uuidapp

  • Every version

    v1 to v8, plus GUID, Nano ID and ULID, each on its own page.

  • Free

    No sign-up and no account. Open a page and copy an ID.

  • Bulk export

    Up to 10,000 at once as CSV, JSON, SQL or text.

  • Plain English

    Every page explains what the ID is and when to use it.

Tools

Need 10,000 UUIDs? Export to CSV, JSON or SQL. Try it free

Questions people ask

What is the difference between a UUID and a GUID?

None in practice. GUID is Microsoft's name for a UUID. Windows tends to show GUIDs in uppercase with braces.

Which UUID version should I use?

UUID v4 for most things. UUID v7 for database primary keys, because it sorts by time. UUID v5 when the same input must always give the same ID.

Are UUIDs really unique?

Not guaranteed, but close enough. With UUID v4 you would need about 2.7 quintillion IDs for a 50% chance of a single repeat.

Is UUID v7 better than v4?

For database keys, usually yes: new IDs land at the end of the index. But v7 reveals when it was made, so v4 is better when that should stay private.

Can I find out when a UUID was created?

Only for time-based versions: v1, v6 and v7. Paste one into the UUID decoder to see the date. v4 and v5 contain no time.

Guides

All guides