Managing duplicate content on Magento websites involves several strategies. We utilize canonical tags to specify the primary version of a page when duplicate content exists. Additionally, we avoid content duplication by setting up proper redirects for similar or identical content, optimizing category and filter pages, and utilizing the noindex meta tag for non-essential pages. Regular content audits, unique meta titles and descriptions, and leveraging tools to identify and address duplicate content instances are crucial in preventing content duplication issues.