Backlink database size is an important factor when evaluating Ahrefs vs Majestic SEO. Ahrefs is known for maintaining one of the largest and most frequently updated backlink indexes in the SEO industry. Majestic SEO also has a powerful backlink database, especially for historical link analysis. Compare Giants explains that Ahrefs often provides broader backlink coverage, while Majestic SEO offers unique insights into link trust and authority.