FAQ

• What is a GUID or UUID?

  A GUID (Globally Unique Identifier) or UUID (Universally Unique Identifier) is a 128-bit value (16 bytes) used to create IDs that are unique without a central registry. Common in Windows, .NET, databases, and APIs. See Wikipedia for more on UUID structure and versions.

• Is my data sent anywhere?

  No. Conversion and generation run entirely in your browser. Nothing is uploaded or stored.

• What does Auto detect do?

  It guesses whether your input is standard dashed GUID, 32 hex characters, Base64 (16 bytes), or a decimal integer. After you click Convert to all formats, that choice is used to parse the value. You can also pick the input type manually from the dropdown.

• Why does the 128-bit integer differ from counting the hex digits as one number?

  Microsoft’s GUID integer follows .NET’s internal byte layout: the first 4+2+2 bytes of the standard string are little-endian in memory, while the last 8 bytes stay in order. Official Microsoft GUID converters use that layout. A different (often larger) decimal comes from reading all 32 hex characters strictly left-to-right as one big-endian integer. This tool matches Microsoft / .NET for the decimal field. Pasting a decimal uses that same Microsoft interpretation.

• Why do Hex and Base64 differ from the standard string’s hex groups stuck together?

  Microsoft tools show 32-character hex and Base64 from Guid.ToByteArray(): the first three fields are little-endian on the wire, so the hex string is not simply the standard groups concatenated. Use a dashed or braced standard GUID if you mean RFC field order; use the Hex input type for a 32-char .NET wire hex string.

• I pasted 32 hex characters with no dashes and the GUID looks wrong.

  Undashed 32-character input is interpreted as .NET / ToByteArray byte order (like PowerShell). If your hex is the concatenation of the standard 8-4-4-4-12 groups in display order, add the dashes (or braces) so the tool reads RFC field order.