Ahrefs vs Surfer SEO, what's best, and why? Check this out. Ahrefs is a full-service SEO toolkit. It's great for keyword research, tracking down backlinks, and evaluating your website. Surfer SEO? It's all about on-page tuning. It looks at keyword density, the length of your content, and other rank-boosting stuff. What's best for you? Are you after a big-picture overview of your website's keyword performance? Then Ahrefs is your guy. Want to tweak every webpage for the most views? Surfer SEO is calling your name. Both stand tall in their own areas. Your SEO aims will guide your pick.