To improve SEO and eliminate duplicate content, ensure that the text and HTML structure of your web pages are unique. Avoid using identical content across multiple pages. If you have similar content, use techniques such as canonicalization to indicate the preferred version to search engines. Remove any unnecessary or redundant HTML elements. Focus on creating high-quality, original content that is relevant and engaging for users and search engines. Avoid relying on CSS styles for conveying meaning; use semantic HTML elements instead. A well-structured and unique HTML document contributes to improved SEO performance.