Same 128 bits, different conventions by platform

A GUID and a UUID are the same underlying value — 128 bits, typically represented as 32 hex digits — but different platforms and tools have settled on different textual conventions for writing that value out. Windows APIs and the registry favor the braced form (`{550e8400-...}`), most Unix tooling and RFC 4122 itself use the plain hyphenated form with no braces, and some contexts (compact identifiers, certain database columns) strip the hyphens entirely to save four bytes. None of these are more "correct" than the others — they're just what each ecosystem standardized on — which is exactly the friction this tool exists to remove: paste whichever form you have, get every other form back at once.

Reformatting, not validating meaning

This tool checks that the input decodes to exactly 32 hex digits — that's the entire validation it performs. It doesn't check the GUID's version/variant bits for structural correctness, doesn't know whether it's actually in use anywhere, and doesn't verify it against any registry or database. That's a deliberate scope boundary: reformatting an existing identifier and generating/validating one are different problems, and this tool exists specifically for the reformatting case — for generating fresh random UUIDs instead, this site's UUID Batch Generator tool is the right one to reach for.