You should measure the success of SEO using several key criteria. First, track organic traffic to see how many visitors come from search engines. You should also monitor keyword rankings to see if your target keywords improve in search results. Conversion rate is important to measure how many visitors take desired actions. You can check bounce rate to see if users are staying on your site. You should track backlinks to ensure you’re earning high-quality links. Page load speed and mobile-friendliness are also essential for user experience. These metrics help evaluate the effectiveness of your SEO efforts.