To download your product information from Google Merchant Center, please follow the tutorial below. This file can be used to alter the data and resubmitted as a supplement feed.
Google Merchant Center Next
Step 1: Log in to Google Merchant Center Next
Step 2: Go to Products > click on All Products
Step 3: On the right hand side, click on the download icon to download all products
Step 4: Open the zip file and extract the file.
Step 5: Change the file name extension from .tsv to .csv and you can open it in your spreadsheet editor.
Google Merchant Center Classic
Download Data Feed
Step 1 : Login to Google Merchant Center
Step 2 : Click on Products > All Products in the left hand menu
Step 3 : Click on the download icon
Step 4 : Open the zip file and extract the file.
Step 5: Change the file name extension from .tsv to .csv and you can open it in your spreadsheet editor.