Our research includes 30 expert total reviews for 2 best deals on external hard drives under $400. The highest average score is 81%, while the lowest is 80% (a gap of 1%). There are about 15 reviews per product. Reviews come from sites like PCMag, Wired, and more. Click on a product to see more information (including which reviews were included). This list gets updated every few days as we routinely add the latest products.