What is IdFix and How to use it?

In this blog, we will install IdFix to identify the errors in your actual victory before you synchronize to Office 365.

 What is IdFix?

Microsoft is functioning to decrease the time called for to remediate identification concerns when onboarding Microsoft 365. A section of this initiative is intended to deal with the moment involved in remediating the Windows Server Active Directory Site reported by the directory synchronization devices such as Azure AD Connect and Azure AD connect cloud sync. The focus of IdFix is to allow you to achieve this job in a straightforward, prudent style. 

Note – This tool does not guarantee to fix all the errors, yet it can fix the majority of errors

So IdFix is a Microsoft tool that identifies the errors such as duplicates formatting problems in your direct domain service before you synchronize to Office 365. IdFix can be run any time in your environment before you start migrating to Office 365 or a hybrid identity setup. And that will help you to fix all the issues related to these duplicates or formatting problems. Then you can have a smooth synchronization between on-premises and Azure Active Directory. And it is not compulsory to run at a fix in your own premises environment, and you can run synchronization directly without running the IdFix. But it is not recommended because, as I said, it is always good to fix errors before you synchronize because this takes less time, and this often provides a more thoughtful transition to the cloud.


To understand the purpose of an IdFixe tool, I would like to start with an example so you can see it from the below image.

To understand the purpose of an IdFixe tool, I would like to start with an example to understand easily. For reference, you can see the above image. Here I have on-premises active directory and a user, imamitsingh, in the Exportal domain controller. So I have two SMTP addresses. One is imamitsingh@exportal.live which is the routable domain.

And I have a second one that is imamitsingh@exportal.local, but that is only routable in the local network, not outside the local network.

So, on on-premises, this attribute is acceptable. That is no Errors.

But when you move to Azure AD, you will get to add, which will stop synchronizing this user from On-premises to Azure AD.

So to avoid this extensive list of users with the different errors, it is always good to run the IdFix, and that will list you out all these errors so you can fix all the issues.

Then you can have a smooth transition to the cloud.

How to use IdFix?

For installation of IdFix, you can visit https://microsoft.github.io/idfix/, which will list out the installation solutions and how to uninstall, what the requirements are, and what patches are available. 

Also, for the installation, you can simply search for the fix and download it from the GitHub and see a one-time execution file.

Now download the file and launch the IdFix tool.

Now Click on the Downloaded exe file and easily install it on on-premises.

Now click on Install button.

This is a very lightweight file, so it quickly completes the installation, as you can see below.

Once the installation completed, you can open the tool and that will list out once you click on the query button, that will list out all the users, its attributes and the value update and then action.

Here you can see error it is showing here is top level domain.

So the reason is my domain is exportal.live and .live Microsoft take as a non-routable domain, and a .live is a routable domain. So I can skip this error.

Now let’s install another domain controller. Now install the IdFix in our old domain controller and see how it works.

In Exchange online, you need to perform the same installation process as earlier discussed in the blog.

So after the installation has been completed and if I click, query, you can see that there is no error found and all the identities are good enough to go to Microsoft 365.

If you found any error you can use action button to update or solve the error.

About double domain addresses are also there with the user. If any user belongs to local will remove the local SMTP addresses, for example, imamitsingh@exportal.local change to imamitsingh@exportal.live.

 For confirmation, you can again click on the query and check if the error still exists or not.


So you can take all the actions from IdFix to remove the duplicate or SMTP addresses or attributes or whatever it is.

So this is how you have to use your IdFix tool in your on-premises before you synchronize your on-premises Domain controller to Azure AD.

hope you like this article, and it’s able to solve your problem. Did you enjoy this article? You may also like How to Disable OWA for New Users?. Don’t forget to share this article.

Amit Singh

Amit Singh

I am a dynamic Tech Enthusiast, specializing in various Microsoft technologies, including Office 365, Exchange, PowerShell, and Active Directory. I loved to helped customers worldwide design, implement, migrate, and secure Exchange and Office 365 through various roles for different employers, and more recently, as an independent consultant.