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UUID Generator

UUID Generator is part of Toolspire and is ready as soon as this page loads. Create random or time-ordered UUIDs straight away, in bulk and in any format — uppercase, no hyphens, {braces} or urn:uuid: — and decode a UUID to see its version and creation time.

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What you can do here

The right version

v4 for general IDs, v7 for database keys, v5 for repeatable IDs from names — each explained in one line.

Bulk generation

Make 10, 100 or 10,000 UUIDs and copy them all or download a .txt file.

Any format

Match your code or database: uppercase for .NET GUIDs, no hyphens for compact keys, quotes and commas for SQL.

Name-based UUIDs

Turn domain names, URLs or any text into stable v5 or v3 UUIDs — one per line.

Decode & validate

Paste a UUID — or a log line containing several — to check it and see when it was created.

Private and offline

UUIDs are made on your device. Nothing is sent to a server or logged.

The sequence

How to generate a UUID

  1. 1

    Pick a version

    Keep v4 for a random UUID, or choose v7 for time-ordered IDs.

  2. 2

    Choose how many

    Enter a number or pick 10, 100 or 1,000.

  3. 3

    Set the format

    Turn on Uppercase, remove Hyphens, or wrap each UUID in braces, quotes or urn:uuid:.

  4. 4

    Copy

    Click Copy (or Copy all), or download the list as a text file.

Worth knowing

  • UUID Generator on Toolspire: generates version 4 (random), version 7 (Unix time, sortable), version 1 (time-based), version 5 (SHA-1) and version 3 (MD5) UUIDs, plus the nil and max UUIDs — all following RFC 9562.
  • Random bits come from your browser’s cryptographically secure generator (Web Crypto).
  • Version 7 UUIDs generated together stay in order even within the same millisecond, which keeps database indexes fast.
  • Version 1 UUIDs use a random node ID, so they never reveal your device’s MAC address.
  • Generate up to 10,000 at once, uppercase or lowercase, with or without hyphens, in {braces}, "quotes" or as urn:uuid:, one per line or comma-separated.
  • The decoder shows any UUID’s version, variant and — for v1, v6 and v7 — the date and time it was created.

Which UUID version should I use?

VersionMade fromUse it for
v4122 random bitsGeneral-purpose unique IDs — the default choice
v7Unix time in ms + random bitsDatabase primary keys and anything you sort by creation time
v1Time + clock sequence + nodeOlder systems that expect time-based UUIDs
v5SHA-1 of a namespace and a nameThe same ID every time for the same input
v3MD5 of a namespace and a nameCompatibility with systems that already use v3

Are UUIDs really unique?

A version 4 UUID has 122 random bits: about 5.3 × 10³⁶ possible values. You would need to generate a billion UUIDs every second for about 86 years before the chance of a single duplicate reached 50%. In practice, UUIDs from a good random source never collide.

UUIDs aren’t secrets, though: don’t use them as passwords or security tokens. And while v7 UUIDs are great database keys, they reveal the time they were created.

FAQ

Questions about UUID Generator

Where does UUID Generator run?

UUID Generator runs in this tab on Toolspire. What you type or drop in is not sent to us and is not stored on a server.

What is the difference between a UUID and a GUID?

None in practice. GUID (globally unique identifier) is Microsoft’s name for a UUID. Windows and .NET often show GUIDs in uppercase and in braces — switch on Uppercase and choose { } to match.

Is UUID v7 better than v4?

For database keys, usually yes: v7 UUIDs increase over time, so new rows go at the end of the index instead of random places, which keeps inserts fast. Use v4 when the creation time shouldn’t be visible.

Are these UUIDs safe to use in production?

Yes. They follow RFC 9562 and use your browser’s cryptographically secure random number generator — the same quality as crypto.randomUUID() or uuid libraries.

How do I check whether a string is a valid UUID?

Open Decode & validate and paste it. The tool accepts common formats — with or without hyphens, braces or urn:uuid: — and shows the version, variant and, for time-based versions, when it was created.

Why does v5 give the same UUID every time?

That’s the point of name-based UUIDs: the same namespace and name always produce the same UUID, so different systems can derive matching IDs without talking to each other.

Can a UUID be decoded to get the time?

For versions 1, 6 and 7, yes — the creation time is stored inside. Version 4 is purely random, and v3 and v5 are hashes, so they contain no time.

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