Any organization that is using Office 365 will want to customize the main login screen for all their users in order to give them a more consistent and familiar experience. Within Office 365, achieving that is simple and straightforward. The organization logo, color schemes, images, etc. can be set on the login page.
However, you must be a global administrator to do that. It must also be noted that all branding options are NOT mandatory. For the options which have no specified styles/images, it will resort to the defaults of Office 365. The steps below explain how to make the customization.
Step 1
Open https://www.office.com and log in using your credentials.
Step 2
After login, open Azure Active Directory Admin Center using the following navigation.
Office 365 - Admin Center - Azure Active Directory
Step 3
Once inside the Azure Active Directory Admin Center, search for Company branding (it can be found under the “Manage” section) and click on it. Clicking on it will open the associated Office 365 accounts – select the one in consideration (illustrated by the image point 3 below).
Step 4
Now, you will get the option of editing the company branding. Upload a sign-in background image. The image size should be less than 300 KBs.
Step 5
Upload a banner logo with image size < 10 KB.
Step 6
Enter some sign-in page text.
Step 7
In advanced settings, you can set up a background color which is visible in the case when the background image is not able to load due to low bandwidth.
Step 8
Upload a square logo image with an image size <10KB
Step 9
Upload a square logo image for the dark theme with an image size <10KB
Step 10
Select the option Yes/No for the option to remain signed in.
These concluded the steps. To have a look at the new and customized login page, sing out from all your Office 365 accounts, close the browser, and sign in again to see your new login page!