A headless CMS separates the content management system from the front-end presentation layer, allowing for greater flexibility and customization. This can improve SEO by allowing developers to optimize the front-end for search engines without being restricted by the CMS. Additionally, headless CMS provides a more user-friendly and faster website experience, both of which are essential ranking factors for search engines. This results in improved website discoverability, faster load times and better user engagement, which can contribute to higher search engine rankings. Essentially the more custom the CMS, which we always recommend Sanity, the better your SEO keywords, schema, and structured data are.