How to Enable SharePoint Designer for SharePoint Online?

Requirement: Enable SharePoint Designer for a SharePoint Online site.

SharePoint Online: How to Connect from SharePoint Designer?

SharePoint Designer is a powerful tool for customizing SharePoint sites. It offers a robust set of features that allow you can create custom web pages, design page layouts, create custom SharePoint Designer workflows, build custom forms, connect to external data sources using external content types such as databases or web services, control the appearance and functionality of your SharePoint site, etc. to take full advantage of the capabilities of SharePoint platform. You can also use SharePoint Designer to create advanced views of lists and libraries and to edit the underlying HTML and CSS code of SharePoint pages. SharePoint Designer is a desktop application that must be downloaded and installed on your computer, You can download the latest version of SharePoint Designer – Microsoft SharePoint Designer 2013 from https://www.microsoft.com/en-us/download/details.aspx?id=35491. After the installation, you can connect to your SharePoint site and make changes to SharePoint Online sites.

By default, SharePoint designer customizations are disabled for modern team sites/group sites in Microsoft SharePoint Online. It gives an error message, “The server could not complete your request.” when you try to open a SharePoint Online group site in SharePoint Designer.

Moreover, It gives a “You do not have permission to open this web site in SharePoint Designer” error message at times:

So, how to connect SharePoint designer to SharePoint Online?

How to Enable SharePoint Designer in SharePoint Online?

Can you use SharePoint designer with SharePoint Online? Does SharePoint designer work with SharePoint Online? Is SharePoint Designer still supported? Of course, yes! To enable SharePoint Designer for SharePoint sites, you have to allow custom script and enable SharePoint Designer at the site collection level!

Step 1: Enable Custom Script in SharePoint Online

Just follow these steps to enable the custom script:

1. Sign in to Office 365 and go to the SharePoint Online Admin Center.
2. Click on Settings from the left navigation >> Click on the “Classic settings page” link >> Scroll down to the “Custom Script” section.
3. Under the Custom Script section, Set “Allow users to run custom script on personal site” and “Allow users to run custom script on self-service created sites” options. 

   

4. Click on “OK” to save your changes.

This enables SharePoint Designer in SharePoint Online. However, this change may take up to 24 hours to reflect. To enable custom script on a particular site collection immediately, use this PowerShell script through SharePoint Online Management Shell. Furthermore, when you enable custom scripting through the web interface, you enable it for all sites in the tenant. But you can enable or disable custom scripting on a specific site collection through PowerShell.

PowerShell to Enable SharePoint Designer in SharePoint Online:

If you want to enable custom script at the site collection level, use this PowerShell script in SharePoint Online Management Shell:

#Set Parameters
$AdminSiteURL="https://Crescent-Admin.sharepoint.com"
$SiteURL="https://crescent.sharepoint.com/sites/creditpipeline"

#Connect to SharePoint Online Admin Center
Connect-SPOService -Url $AdminSiteURL -Credential (Get-Credential)

#Enable SharePoint Designer for the site collection
Set-SPOSite -Identity $SiteURL -DenyAddAndCustomizePages $False

To disable SharePoint Designer customization for a SharePoint Online site collection, use the following:

#Disable SharePoint Designer for the site collection
Set-SPOSite -Identity $SiteURL -DenyAddAndCustomizePages $True

Step 2: Enable SharePoint Designer for the Site

Once the custom script is enabled, the next step is to ensure SharePoint Designer is enabled at the site collection.

1. Navigate to your SharePoint Online site >> Click on Settings >> Site information >> View All Site Settings.
2. Click on “SharePoint Designer Settings” under Site Collection Administration.
3. Check “Enable SharePoint Designer”.

You can also enable SharePoint Designer for the site using PowerShell:

#Config Variables
$SiteURL = "https://crescent.sharepoint.com/sites/retail"
 
Try {
    #Connect to PnP Online
    Connect-PnPOnline -Url $SiteURL -Interactive
     
    #Get the site SharePoint Designer settings
    $Site = Get-pnpsite -Includes AllowDesigner

    If($Site.AllowDesigner -eq $false)
    {
        #Enable SharePoint Designer
        $Site.AllowDesigner = $true
        Invoke-PnPQuery
        Write-host "SharePoint Desingner Enabled Successfully!" -f Green
    }
    Else
    {
        Write-host "SharePoint Desingner is already Enabled!" -f Yellow
    }
}
Catch {
    write-host "Error: $($_.Exception.Message)" -foregroundcolor Red
}

Open SharePoint Online site in SharePoint Designer

Once the custom script is enabled, you can access SharePoint Online sites with SharePoint Designer with Site Collection Administrators / Site Owners or Designer permissions. To open the Sharepoint Online site from SharePoint Designer, do the following:

1. Open Sharepoint Designer and select the “Open Site” button from the File menu.
2. Enter the URL of your SharePoint site into the dialog box that appears, and then click “Open.”
3. Click on the page or workflow you want to customize in the left-hand navigation pane.
4. Make your changes in the right-hand pane, using either the graphical interface or the HTML/CSS editor.
5. Save your changes by clicking “Save” in the File menu.

You can also enable custom script with PnP PowerShell: How to Enable Custom Script in SharePoint Online using PowerShell?