GUID Generator
Make new GUIDs, uppercase in braces or any form, up to 100,000 at once. Or paste yours to check them. Nothing leaves your browser.
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Your new GUID
Press Generate (Alt G) for 10 at once, or paste GUIDs in the editor to check them.
On this page
About GUID Generator
Updated
GUID Generator makes new GUIDs in the form Windows and Visual Studio use: uppercase, in braces. Press Generate for as many as you need. Paste GUIDs from a project file, the registry or a database, and each line is checked and decoded.
A GUID is a UUID with a Microsoft name. For lowercase UUIDs without braces, the UUID Generator starts in that form. Both pages make the same IDs.
How to use it
- Set Count (1 to 100,000) next to Generate; on a phone it is under More. Version starts on v4 (random), the same as
Guid.NewGuid(). - Press Generate (Alt G). The GUIDs replace the editor text; Undo brings the old text back.
- Change the form in Options: Case, Hyphens, Wrap in (braces, parentheses,
urn:uuid:, quotes) and Separator (a comma after each one, for a list in code or SQL). - To check GUIDs, paste them one per line. Results shows each line, and Format (Alt F) rewrites the valid ones in your form.
GUID forms
The same GUID, in the four forms .NET names with a letter, plus the URN. The tool reads all five.
D de310cf8-857b-4462-aee0-c5dd6254de60
N de310cf8857b4462aee0c5dd6254de60
B {de310cf8-857b-4462-aee0-c5dd6254de60}
P (de310cf8-857b-4462-aee0-c5dd6254de60)
urn:uuid:de310cf8-857b-4462-aee0-c5dd6254de60The tool reads D, N, B, P and URN, in upper or lower case, and with quotes and a comma around them. Wrap in in Options writes braces, parentheses, urn:uuid: or quotes, and Separator puts a comma after each one. Case does not change a GUID: DE310CF8... and de310cf8... are the same one.
Common errors
A letter O for a zero
A GUID typed from a screen or a printout picks up letters that look like digits. Only 0 to 9 and A to F are allowed.
{47976E55-CE4B-4254-8EC3-34B16DFDCD9O}
Character 37 is "O". A GUID uses only 0 to 9 and a to f. Letter O looks like zero; use 0.{47976E55-CE4B-4254-8EC3-34B16DFDCD90}The same GUID twice
A GUID copied from one project to another is no longer unique. Visual Studio and installers can fail in odd ways when two projects share one. The tool notes the second one.
{DE310CF8-857B-4462-AEE0-C5DD6254DE60}
{DE310CF8-857B-4462-AEE0-C5DD6254DE60}
Line 2: Same GUID as line 1. Delete one, or Generate a new one.Give the copy a new GUID: Generate one and paste it in.
An old GUID with no version
Some COM GUIDs from the 1990s, such as {00020906-0000-0000-C000-000000000046} for a Word document, use the Microsoft variant. They are valid, but carry no version. The tool notes this; you do not need to change them.
GUID resources
- RFC 9562: Universally Unique IDentifiers (UUIDs)The standard since 2024. It replaces RFC 4122 and adds versions 6, 7 and 8 and the max UUID.
- Universally Unique Identifier on WikipediaThe history of UUIDs, each version, and the odds of a collision.
- Microsoft: Guid StructThe .NET Guid type, with NewGuid, CreateVersion7, Empty and AllBitsSet.
- Python: uuid moduleuuid1 and uuid3 to uuid8 (version 2 is left out on purpose), the namespaces, and the nil and max values.
- PostgreSQL: UUID Functionsgen_random_uuid, uuidv7 and the functions that read the version and time of a UUID.
- uuid on GitHubThe JavaScript package this tool uses to make UUIDs: v1, v3 to v7, nil and max.
GUID FAQ
What is a GUID generator?
A GUID generator makes globally unique identifiers: 128-bit IDs such as {DE310CF8-857B-4462-AEE0-C5DD6254DE60}. Windows, .NET and SQL Server use them for keys, COM classes, project files and registry entries. This one makes up to 100,000 at a time and checks the GUIDs you paste.
What is the difference between a GUID and a UUID?
As text, none. GUID is Microsoft's name for a UUID, and both follow the same standard, now RFC 9562. Microsoft tools often write GUIDs in uppercase and in braces, while other systems write UUIDs in lowercase without them.
As bytes, there is one difference. .NET's Guid.ToByteArray() and SQL Server's uniqueidentifier store the first three groups byte-reversed (little-endian). So the same GUID gives different raw bytes in .NET than in Java, Python or PostgreSQL. In .NET 8 and up, ToByteArray(true) gives the standard order.
How do I generate a GUID?
Press Generate on this page, or copy the one the Result shows when the page opens.
In C#: Guid.NewGuid(). In PowerShell: New-Guid. In SQL Server: SELECT NEWID();. In Visual Studio: Tools > Create GUID. Use .ToString("B").ToUpperInvariant() in C# for the {UPPERCASE} form.
How do I make a 32-character GUID?
Leave out the hyphens. In Options, turn Hyphens off, and Generate gives 32 hex digits, such as DE310CF8857B4462AEE0C5DD6254DE60. In .NET it is the N format: Guid.NewGuid().ToString("N"). The tool reads this form back and checks it like any other.
What is a GUID used for?
To name a thing so that no other thing anywhere has the same name, without a central list. Database rows, files, COM classes and interfaces, Visual Studio projects, installer packages, devices and Windows registry keys all use them. Two systems can make IDs on their own and later merge them without clashes.
How can I generate a GUID in Excel?
Excel has no GUID function. This formula makes a random (v4) GUID in Excel and Google Sheets:
=UPPER(DEC2HEX(RANDBETWEEN(0,4294967295),8)&"-"&DEC2HEX(RANDBETWEEN(0,65535),4)&"-4"&DEC2HEX(RANDBETWEEN(0,4095),3)&"-"&DEC2HEX(RANDBETWEEN(8,11))&DEC2HEX(RANDBETWEEN(0,4095),3)&"-"&DEC2HEX(RANDBETWEEN(0,16777215),6)&DEC2HEX(RANDBETWEEN(0,16777215),6))
It changes each time the sheet recalculates. Copy the cells and use Paste Values to keep them. For many GUIDs, make them here and paste the list in one go.
Can two GUIDs be the same?
In theory, yes. In practice, no. A random GUID has 122 random bits, so you would need about 2.7 quintillion of them for a 50% chance of one clash. When you see the same GUID twice, it was copied, not made twice. The tool marks a GUID that is in your list twice.
Which GUID format should I use?
The one your system reads. .NET reads every common form: D (with hyphens), N (32 digits), B (braces) and P (parentheses). The registry and .reg files use braces. SQL Server shows uppercase with hyphens. JSON and URLs mostly use lowercase with hyphens.
Set the form in Options, and Format (Alt F) rewrites a whole list that way.
Are my GUIDs sent anywhere?
No. The tool makes and checks GUIDs in your browser, with the browser's own random numbers. Nothing is uploaded. You can check this in your browser's network tab while you use it.