SharePoint Online: Get Files and Sub-Folders Count on Each Folder in a Document Library using PowerShell

Requirement:  Get the count of files and sub-folders at each folder in a SharePoint Online document library.

How to Get the Number of Files and Sub-Folders at Each Folder of a Document Library?
When a document library has multiple folders, sub-folder and files, you can get the number of files and sub-folders at each level by adding "Folder Child Count" and "Item Child Count" fields to the view.

• Navigate to the document library >> Click on View drop-down menu >> "Edit Current View"
• Select "Folder Child Count" and "Item Child Count" columns and Click on OK.

Now, the view shows the number of sub-folders and the number of items at the top-level of each folder.

Get Files, Sub-Folders Count at Each Folder in a Document Library using PowerShell
Here is the PowerShell to find the number of files and sub-folders at each folder in a SharePoint Online document library using PnP PowerShell.

#Parameters
$SiteURL = "https://crescent.sharepoint.com/sites/marketing"
$ListName = "Project Documents"

#Function to get number of Sub-folder and Files count recursively
Function Get-SPOFolderStats
{
    [cmdletbinding()]
    param
    (
        [Parameter(Mandatory=$true,ValueFromPipeline=$true)][Microsoft.SharePoint.Client.Folder]$Folder
    )
    #Get Sub-folders of the folder
    Get-PnPProperty -ClientObject $Folder -Property ServerRelativeUrl, Folders | Out-Null

    #Get the SiteRelativeUrl
    $Web = Get-PnPWeb -Includes ServerRelativeUrl
    $SiteRelativeUrl = $Folder.ServerRelativeUrl -replace "$($web.ServerRelativeUrl)", ""

    [PSCustomObject] @{
        Folder    = $Folder.Name
        Path      = $Folder.ServerRelativeUrl
        ItemCount = Get-PnPFolderItem -FolderSiteRelativeUrl $SiteRelativeUrl -ItemType File | Measure-Object | Select -ExpandProperty Count
        SubFolderCount = Get-PnPFolderItem -FolderSiteRelativeUrl $SiteRelativeUrl -ItemType Folder | Measure-Object | Select -ExpandProperty Count
    }
    
    #Process Sub-folders
    ForEach($SubFolder in $Folder.Folders)
    {
        Get-SPOFolderStats -Folder $SubFolder
    }
}

#Connect to SharePoint Online
Connect-PnPOnline $SiteURL -Credentials (Get-Credential)

#Call the Function to Get the Library Statistics - Number of Files and Folders at each level
$FolderStats = Get-PnPList -Identity $ListName -Includes RootFolder | Select -ExpandProperty RootFolder | Get-SPOFolderStats | Sort Path
$FolderStats

#Export to CSV 
$FolderStats | Export-Csv -Path "C:\Temp\DocLibStats.csv" -NoTypeInformation

This script outputs the data on screen and also generates a CSV file!