Generate random version-4 UUIDs — identifiers unique enough to use as database keys, request IDs or file names without a central authority. Choose how many you need and copy them in one go. They’re produced by your browser’s cryptographic random generator, so nothing is fetched from a server.
Version-4 UUIDs from your browser’s secure random generator. Identifiers, not secrets — use the password generator for credentials.
How it works
Each UUID is 128 bits written as 32 hexadecimal digits in the familiar 8-4-4-4-12 grouping. Version 4 means the bits are random except for a fixed version marker (the “4”) and a variant marker — this tool uses the platform’s crypto.randomUUID, which draws from a cryptographically secure random source.
The formatting options are cosmetic and don’t change the identity: uppercase for systems that expect it, braces for the Microsoft GUID style like {…}, and hyphen removal for compact 32-character keys. Generation happens entirely on your device, so the values are never seen by anyone else — including us.
Practical examples
Seeding database rows
Need ten primary keys for test data? Set the count to 10, generate, and copy the whole list — each one a valid UUID like 3f2504e0-4f89-41d3-9a0c-0305e82c3301.
A Microsoft-style GUID
For a Windows config or .NET code that expects braces, enable braces and uppercase to get {3F2504E0-4F89-41D3-9A0C-0305E82C3301}.
Compact IDs without hyphens
Turn off hyphens for a 32-character token suitable for filenames or URL slugs where dashes are awkward: 3f2504e04f8941d39a0c0305e82c3301.
Frequently asked questions
What is a UUID?
A Universally Unique Identifier is a 128-bit value written as 36 characters (32 hex digits plus four hyphens). It’s designed so that anyone can generate one independently and it will, in practice, never collide with another — no central registry needed.
What does “version 4” mean?
UUIDs come in several versions. Version 4 is almost entirely random, which makes it the go-to for general-purpose IDs. Other versions encode a timestamp or a name hash; this tool generates v4, the most common choice.
Are these UUIDs really unique?
Not guaranteed, but the odds of a collision are astronomically small — you’d need to generate billions per second for many years to have a realistic chance. For application keys, request IDs and similar uses, they’re treated as unique.
Are they random enough to be unguessable?
They use the browser’s cryptographically secure generator (crypto.randomUUID), so they can’t be predicted. That said, a UUID is an identifier, not a secret — for passwords or tokens, use a dedicated generator built for that purpose.
What’s the difference between a UUID and a GUID?
They’re the same thing. “GUID” is Microsoft’s name for a UUID and is often written in braces and uppercase. Enable those options here to produce the GUID style; the underlying value is identical.
Do the uppercase or brace options change the value?
No. Case, braces and hyphens are display conventions only — {3F25…} and 3f25… are the same UUID. Most systems compare them case-insensitively and ignore the braces.
Are the generated UUIDs sent anywhere?
No. They’re created by your browser and stay on your device. Nothing is requested from a server and analytics never receives the values.
How many can I generate at once?
From 1 to 1000 per batch. Ask for more and it’s capped at 1000 to keep the page responsive; click generate again for another batch.
Can I use a UUID as a password?
It’s not ideal. A v4 UUID has about 122 bits of randomness, which is strong, but its fixed format is recognisable and it isn’t meant as a secret. Use the password generator for credentials.
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