ImmutableID ↔ objectGUID

Convert an on-prem objectGUID to the Entra ImmutableID and back.

Why this exists

Hybrid identity matching breaks when the source anchor (ms-DS-ConsistencyGuid / objectGUID) and the cloud ImmutableID don't line up. The little-endian byte-order swap is the part everyone gets wrong.

How to use

Paste either an objectGUID or a base64 ImmutableID into the one box.
It detects which one you pasted and converts automatically, showing both.
The reorder of the first three GUID fields is handled for you.

objectGUID or ImmutableID

Paste either side

Drop in an on-prem objectGUID (braces, dashes and case are all optional) or a cloud ImmutableID (from Get-MgUser -Property OnPremisesImmutableId). It works out which one you pasted and shows both, handling the little-endian byte swap of the first three GUID fields for you.