This is the simplest way to prevent downloads for specific files or folders without changing overall site permissions. Select the file or folder and click . Click the gear icon ( Settings ) in the share popup. Change the permission to Can view . Toggle the Block download switch to "On". Click Apply and send the link to your recipient. Method 2: Creating a Custom "No Download" Permission Level
Name it (e.g., "Read – No Download") and the following boxes: Open Items (under List Permissions) Use Client Integration Features (under Site Permissions) Click Create . prevent download from sharepoint
Select an existing level like or Edit , scroll to the bottom, and click Copy Permission Level . This is the simplest way to prevent downloads