Highlighter is a free SEO Analyzer Extension designed for Chrome, providing users with a robust set of tools to optimize their website's performance and visibility. It visualizes page structure and highlights essential elements such as titles, paragraphs, and image alt texts, making it easier to assess a webpage's SEO health. The extension allows users to display meta titles, descriptions, and icons, while also verifying the presence of an SSL certificate and checking Google cache status.

In addition to these features, Highlighter counts titles, displays average lengths, and offers an Hn panel for structured data analysis. Users can highlight follow tags, external links, and indexed backlinks, with the option to eliminate stop words and count word occurrences in paragraphs. The tool also includes a notes panel for documentation, integrates with GPT-3.5 or 4 Chat API for direct interaction, and provides insights into duplicate titles and 404 pages, ensuring a comprehensive approach to enhancing SEO strategies directly within the browser.