SharePoint Online: Change Idle Session Timeout Settings

Task: Set idle session timeout value for SharePoint Online.

How to Set SharePoint Online Idle Session Timeout?
Idle session timeout in SharePoint Online is a security mechanism which warns and sign outs the user after a period of inactivity. By default, idle session timeout settings are disabled in SharePoint Online. To set default session timeout values, use the PowerShell cmdlet: Set-SPOBrowserIdleSignOut

The idle timeout settings are applicable only to web browsers - doesn't affect any clients such as OneDrive Sync client - they stay logged in as usual.

SharePoint Online: Configure Idle Session Timeout using PowerShell
Open SharePoint Online Management Shell and run this PowerShell script to change SharePoint online session timeout:

#Set Config parameters
$AdminSiteURL = "https://crescent-admin.sharepoint.com/"

#Connect to SharePoint Online Tenant Admin
Connect-SPOService -URL $AdminSiteURL -Credential (Get-Credential)

#Get Current Idle session Timeout values
Get-SPOBrowserIdleSignOut

#Change Session Timeout Value
Set-SPOBrowserIdleSignOut -Enabled $true -WarnAfter (New-TimeSpan -Minutes 30) -SignOutAfter (New-TimeSpan -Minutes 60)

#Verify the settings
Get-SPOBrowserIdleSignOut

Tips: You can use "Get-SPOBrowserIdleSignOut" to get the current idle session timeout value!

So, after the execution of the above script, SharePoint Online gives a warning after 30 Minutes.If the users press the continue button, they can continue working until the next time they leave the browser window idle for the warning period configured.

and if there are no activity from the end user, then SharePoint Online automatically redirects to sign out page.

Please note: Changes to the idle session settings takes effect ONLY on new sessions. Existing browser sessions doesn't get affected (until user close and re-open a new browser session!). Also, if the user selected "Keep me Signed in" - these timeout settings doesn't affect that user!.

How to Disable Idle Session Timeout in SharePoint Online?
To Disable Idle session timeout, use:

Set-SPOBrowserIdleSignOut -Enabled $False