SharePoint Online: Delete Attachments from List Item using Powershell

Requirement: Delete Attachment from SharePoint Online List Item.

How to Delete Attachments from List Items in SharePoint Online?
To delete an attachment from SharePoint list items,

Navigate to the SharePoint Online List >> Select the List Item >> Click on Edit from tool pane.
In Edit panel, scroll down to the bottom and click on little x Icon next to any attachment to delete it from the list item.
Click on Save to commit your changes.

Delete All Attachments from a List Item using PowerShell:

#Load SharePoint CSOM Assemblies
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.dll"
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.Runtime.dll"

#Set Parameters
$SiteURL= "https://crescent.sharepoint.com"
$ListName="Projects"
$ItemID="4"

Try {
    #Setup Credentials to connect
    $Cred = Get-Credential
    $Cred = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($Cred.UserName,$Cred.Password)
     
    #Setup the context
    $Ctx = New-Object Microsoft.SharePoint.Client.ClientContext($SiteURL)
    $Ctx.Credentials = $Cred
 
    #Get the List & List Item
    $List = $Ctx.Web.Lists.GetByTitle($ListName)
    $Ctx.Load($List)
    $ListItem = $List.GetItemByID($ItemID)
    $Ctx.Load($ListItem)
    $Ctx.ExecuteQuery()
 
    #Get All existing attachments
    $AttachmentFiles = $ListItem.AttachmentFiles
    $Ctx.Load($AttachmentFiles)
    $Ctx.ExecuteQuery()
 
    ForEach($AttachmentFile in $AttachmentFiles)
    {
        $AttachmentFile.DeleteObject()
        $Ctx.ExecuteQuery()
 
        write-host  -f Green "Attachment File '$AttachmentFile' Removed from List Item!"
    }
}
Catch {
    write-host -f Red "Error Removing Attachment From List!" $_.Exception.Message
}

PowerShell to Remove Attachment from SharePoint Online List Item:

#Load SharePoint CSOM Assemblies
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.dll"
Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\Microsoft.SharePoint.Client.Runtime.dll"

Function Remove-AttachmentFromListItem()
{
    param
    (
        [Parameter(Mandatory=$true)] [string] $SiteURL,
        [Parameter(Mandatory=$true)] [string] $ListName,
        [Parameter(Mandatory=$true)] [string] $ItemID,
        [Parameter(Mandatory=$false)] [string] $AttachmentFileName
    )    
    Try {
        #Setup Credentials to connect
        $Cred = Get-Credential
        $Cred = New-Object Microsoft.SharePoint.Client.SharePointOnlineCredentials($Cred.UserName,$Cred.Password)
    
        #Setup the context
        $Ctx = New-Object Microsoft.SharePoint.Client.ClientContext($SiteURL)
        $Ctx.Credentials = $Cred

        #Get the List & List Item
        $List = $Ctx.Web.Lists.GetByTitle($ListName)
        $Ctx.Load($List)
        $ListItem = $List.GetItemByID($ItemID)
        $Ctx.Load($ListItem)
        $Ctx.ExecuteQuery()

        #Get All existing attachments
        $AttachmentFiles = $ListItem.AttachmentFiles
        $Ctx.Load($AttachmentFiles)
        $Ctx.ExecuteQuery()

        #Check if attachment file name exists
        $AttachmentFile = $AttachmentFiles | where { ($_.FileName -eq $AttachmentFileName) }
        If($AttachmentFile -ne $Null)
        {
            $AttachmentFile.DeleteObject()
            $Ctx.ExecuteQuery()

            write-host  -f Green "Attachment File '$AttachmentFileName' Removed from List Item!" 
        }
        else
        {
            write-host -f Yellow "Attachment File '$AttachmentFileName' Doesn't Exist!"
        }
    }
    Catch {
        write-host -f Red "Error Removing Attachment From List!" $_.Exception.Message
    }
}

#Set Parameters
$SiteURL= "https://crescent.sharepoint.com"
$ListName="Projects"
$ItemID="64"
$AttachmentFileName="ProjectProposal.docx"

#Call the function to copy list items
Remove-AttachmentFromListItem -SiteURL $SiteURL -ListName $ListName -ItemID $ItemID -AttachmentFileName $AttachmentFileName

PnP PowerShell to Delete Attachment from SharePoint Online List Item:

#Config Variables
$SiteURL = "https://crescenttech.sharepoint.com"
$ListName ="Projects"
$ListItemTitle = "SharePoint 2016 Upgrade"
$AttachmentFileName= "Project Proposal.docx"

#Connect PNP Online
Connect-PnPOnline -Url $SiteURL -Credentials (Get-Credential)

#Get the Context
$Context = Get-PnPContext
 
#Get the List Item from "Title" field value
$Query = "<View><Query><Where><Eq><FieldRef Name='Title'/><Value Type='Text'>$ListItemTitle</Value></Eq></Where></Query></View>"
$ListItem = Get-PnPListItem -List $ListName -Query $Query -PageSize 1
 
#Get List attachment by its file name
$Attachment = $ListItem.AttachmentFiles.GetByFileName($AttachmentFileName)

#Delete the attachment
$Attachment.DeleteObject() 
$Context.ExecuteQuery()

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