For our free users, you can search by UPC or ISBN when using the barcode scanner on the mobile app. The barcode scanner can do it, or the manual search above the barcode scanner. When using the mobile app, you will find the Barcode Scan button on the top right of the Search tab.
If you're a Pro or Patron subscriber, you can use the Bulk Add/Edit tool to search by UPC or ISBN on the website.