bidirectional · runs in your browser
GUID to ImmutableID Converter
Convert a Microsoft Entra ID objectGUID to the Base64 ImmutableID (sourceAnchor) and back, for hybrid identity.
GUID → ImmutableID
ImmutableID → GUID
PowerShell quick reference
Read the ImmutableID of a cloud user
Get-MsolUser -UserPrincipalName user@contoso.com | Select ImmutableId # or via Graph PowerShell: Get-MgUser -UserId user@contoso.com -Property OnPremisesImmutableId
Match an onprem AD user to a cloud user
$guid = (Get-ADUser jdoe -Properties objectGUID).objectGUID $immutable = [System.Convert]::ToBase64String($guid.ToByteArray()) Set-MsolUser -UserPrincipalName jdoe@contoso.com -ImmutableId $immutable
Read the objectGUID of an AD user
Get-ADUser jdoe -Properties objectGUID | Select objectGUID
About this tool
Convert an Active Directory objectGUID to the Base64 ImmutableID used by Microsoft Entra ID (Azure AD), and back again. This is the value that links an on-premises user to its synced cloud identity, and getting it wrong is a common cause of hard-matching and migration headaches.
Paste a GUID or an ImmutableID and the tool returns the other representation instantly, in your browser. It is built for admins running hybrid identity, ADConnect troubleshooting or tenant-to-tenant migrations.
Frequently asked questions
What is the ImmutableID?+
It is the Base64-encoded form of the on-premises objectGUID, stored on the Entra ID user as the sourceAnchor. It must stay constant for the lifetime of the synced object, hence "immutable".
When do I need to convert it manually?+
Commonly during hard-matching a cloud user to an on-prem account, fixing a broken sync, or migrating identities, where you set ImmutableID with PowerShell using the converted value.
Does the conversion happen online?+
No. The GUID/Base64 conversion is pure math done in your browser, so directory identifiers never leave your machine.