TFT

UUID to GUID Converter (Windows Format)

Convert standard UUID strings to Microsoft GUID format (with braces) and vice versa. This tool handles the formatting differences, making identifiers compatible with Windows systems, .NET, and COM applications.

Converting UUID → GUID

Accepts both formats - will auto-detect and convert

UUID vs GUID Format

UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) are essentially the same 128-bit value, but differ in conventional representation.

UUID (RFC 4122)

550e8400-e29b-41d4-a716-446655440000

Lowercase, with hyphens, no braces

GUID (Microsoft)

{550E8400-E29B-41D4-A716-446655440000}

Uppercase, with hyphens, with braces

Note: In most practical applications, UUID and GUID are used interchangeably. The main difference is formatting convention, not the underlying value.

How the UUID to GUID Converter Works

This converter transforms UUIDs between RFC 4122 standard format and Microsoft GUID format. The underlying 128-bit value stays identical—only the text representation changes.

The tool auto-detects your input format. If you paste a UUID with curly braces, it converts to standard UUID format. If you paste a plain UUID, it converts to GUID format with optional braces.

Format comparison:

UUID (RFC 4122)

550e8400-e29b-41d4-a716-446655440000

GUID (Microsoft)

{550E8400-E29B-41D4-A716-446655440000}

Real Use Cases

Windows Registry editing

A system administrator copies a UUID from a Linux config file and needs it in GUID format with braces for Windows Registry entries.

COM/ActiveX development

A C# developer working with COM interfaces needs GUIDs in the brace-delimited format that Visual Studio expects for IID and CLSID attributes.

Cross-platform database migration

Migrating from SQL Server (which uses GUID) to PostgreSQL (which uses UUID) requires converting the text representation while preserving the value.

API integration

An API returns UUIDs in RFC format, but a legacy Windows service expects GUIDs with braces. The converter bridges the format gap.

Configuration file standardization

A DevOps engineer consolidates configs from multiple sources and needs all identifiers in a consistent format.

Debugging Windows event logs

Event Viewer shows GUIDs with braces, but log aggregation tools expect standard UUID format without them.

What to Know Before Using

Same value, different format: UUID and GUID represent the same 128-bit number. The conversion is purely cosmetic—like changing date formats from MM/DD/YYYY to DD-MM-YYYY.

Case convention: UUIDs are typically lowercase (RFC 4122 convention). GUIDs are typically uppercase (Microsoft convention). This tool follows those conventions automatically.

Braces are optional: When converting to GUID format, you can choose whether to include the curly braces. Some Windows APIs require them; others accept plain hyphenated format.

Byte order note: True GUID byte order conversion (little-endian vs big-endian) is NOT performed. This tool only changes text formatting. For most applications, this is correct—byte order matters only in binary serialization.

FAQ

Are UUID and GUID the same thing?

Yes. GUID (Globally Unique Identifier) is Microsoft's trademarked term for UUID (Universally Unique Identifier). They're both 128-bit values. The difference is purely in how they're typically written: GUIDs use uppercase with braces, UUIDs use lowercase without braces.

When do I need curly braces around my GUID?

Windows Registry entries, COM/DCOM interfaces, and some .NET attributes require braces. Many modern Windows APIs accept GUIDs without braces. When in doubt, include them for Windows-specific contexts.

Why does my GUID look different after conversion?

If only the case changed (lowercase to uppercase or vice versa), that's expected convention. If the actual hex digits changed, you may have encountered a byte-order conversion issue—this tool doesn't perform byte-order swaps, which is correct for most text-based conversions.

Can I convert a GUID back to UUID?

Yes, the conversion is reversible. Paste a GUID with or without braces, and the tool will output standard UUID format (lowercase, hyphenated, no braces).

What happens if I paste an invalid format?

The tool validates that your input contains exactly 32 hexadecimal characters (ignoring hyphens and braces). If validation fails, you'll see an error message explaining the expected format.

Does this work with UUID versions other than v4?

Yes, the converter works with any valid UUID/GUID regardless of version (v1, v3, v4, v5, etc.). The version bits are preserved during conversion.