# Rank-O-Saur > Rank-O-Saur is a free Chrome extension for on-page and technical SEO analysis. It inspects a page's title tag, meta description, canonical, robots directives, headings, content, links, images, structured data, Core Web Vitals, rendering (SSR vs CSR) and AI-crawler accessibility — directly in the browser. This site hosts the extension's homepage and a comprehensive SEO knowledge base. ## Main Pages - [Homepage](https://rankosaur.com/): Overview of the Rank-O-Saur SEO extension, its features and how to install it. - [Changelog](https://rankosaur.com/changelog): Version history and recent updates to the extension. - [SEO Knowledge Base](https://rankosaur.com/en/wiki/): Index of all SEO guides, with code examples and best practices. ## SEO Wiki Guides - [Title Tag](https://rankosaur.com/en/wiki/title-tag): The most important on-page tag — ideal pixel length and keyword placement. - [Meta Description](https://rankosaur.com/en/wiki/meta-description): Writing snippets that increase click-through rate from the search results. - [Canonical Tag](https://rankosaur.com/en/wiki/canonical-tag): Consolidating duplicate content signals to a single primary URL. - [Meta Robots Tag](https://rankosaur.com/en/wiki/meta-robots-tag): Page-level indexing control with noindex and nofollow directives. - [robots.txt](https://rankosaur.com/en/wiki/robots-txt): Controlling web crawlers, crawl budget and blocking AI bots. - [X-Robots-Tag](https://rankosaur.com/en/wiki/x-robots-tag): Controlling the indexing of non-HTML files via HTTP response headers. - [XML Sitemap](https://rankosaur.com/en/wiki/sitemap-xml): Helping search engines discover and prioritize your pages. - [Core Web Vitals](https://rankosaur.com/en/wiki/core-web-vitals): Google's LCP, INP and CLS performance and user-experience metrics. - [Language & Hreflang](https://rankosaur.com/en/wiki/hreflang): International SEO with the HTML lang attribute and hreflang tags. - [JSON-LD Structured Data](https://rankosaur.com/en/wiki/json-ld-markups): Earning rich results with Schema.org structured data. - [URLs & Status Codes](https://rankosaur.com/en/wiki/url-structure): SEO-friendly URL structure and HTTP status codes (200, 3XX, 4XX, 5XX). - [Heading Structure](https://rankosaur.com/en/wiki/heading-structure): Using H1–H6 headings and building a logical content hierarchy. - [Content & Readability](https://rankosaur.com/en/wiki/content-readability): Content length, search intent and the Flesch Reading Ease score. - [Image SEO](https://rankosaur.com/en/wiki/image-seo): Alt text, file size, compression and modern image formats. - [Link Analysis](https://rankosaur.com/en/wiki/link-analysis): Internal and external links, nofollow, redirects (3XX) and broken links (4XX). - [Open Graph & Twitter Cards](https://rankosaur.com/en/wiki/open-graph): Controlling how pages look when shared on social media. - [Rendering (SSR vs CSR)](https://rankosaur.com/en/wiki/rendering): Server-side vs client-side rendering and JavaScript SEO. - [llms.txt & AI Crawlers](https://rankosaur.com/en/wiki/llms-txt): The llms.txt standard, AI crawlers and Generative Engine Optimization. - [Crawl Budget](https://rankosaur.com/en/wiki/crawl-budget): Crawl capacity limit, crawl demand, crawl stats and how to stop wasting crawl budget. - [Indexing](https://rankosaur.com/en/wiki/indexing): Discovery, crawling, rendering and index selection, plus every page indexing report status. - [Duplicate Content](https://rankosaur.com/en/wiki/duplicate-content): Internal and external duplicates, near-duplicates, canonical vs 301 vs noindex. - [Link Juice & Link Equity](https://rankosaur.com/en/wiki/link-equity): The PageRank model, damping factor, nofollow and steering internal link equity. - [Domain Popularity](https://rankosaur.com/en/wiki/domain-popularity): Link, domain, IP and C-class popularity and what these link metrics measure. - [Entity SEO](https://rankosaur.com/en/wiki/entity-seo): Entities, the Knowledge Graph, sameAs and optimising for semantic and AI search. - [Backlinks](https://rankosaur.com/en/wiki/backlinks): Backlink quality markers, link types, vetting sources and link building methods. - [Anchor Text](https://rankosaur.com/en/wiki/anchor-text): Anchor text types, healthy distribution, internal rules and over-optimisation. - [Link Attributes](https://rankosaur.com/en/wiki/link-attributes): The rel attribute reference: nofollow, sponsored, ugc, noopener, canonical, alternate. - [Internal Linking](https://rankosaur.com/en/wiki/internal-linking): Click depth, hub pages, topic clusters, orphan pages and link equity distribution. - [Redirects](https://rankosaur.com/en/wiki/redirects): 301, 302, 307 and 308, redirect chains and loops, link equity loss and when a 404 is the better answer. - [Pagination](https://rankosaur.com/en/wiki/pagination): Self-canonical vs page 1, why rel=prev/next is dead, infinite scroll, noindex and crawl budget. - [Faceted Navigation](https://rankosaur.com/en/wiki/faceted-navigation): The combinatorial URL problem, which filters to index and robots.txt vs noindex vs canonical. - [Breadcrumbs](https://rankosaur.com/en/wiki/breadcrumbs): The three jobs of a breadcrumb, hierarchical vs history-based and valid BreadcrumbList markup. - [Mobile-First Indexing](https://rankosaur.com/en/wiki/mobile-first-indexing): Why the mobile version is indexed, content parity and the typical gaps in text, links and markup. - [HTTPS, SSL and TLS](https://rankosaur.com/en/wiki/https): The TLS handshake, DV/OV/EV certificates, mixed content, HSTS and HTTP-to-HTTPS migration. - [PageRank](https://rankosaur.com/en/wiki/pagerank): The original Brin and Page formula, random surfer model, damping factor and the end of toolbar PageRank. - [Referring Domains](https://rankosaur.com/en/wiki/referring-domains): Referring domains vs backlinks, the links-per-domain ratio, growth patterns and recovering lost links. - [Domain Authority](https://rankosaur.com/en/wiki/domain-authority): Moz DA, Ahrefs DR, Majestic Trust Flow compared, the logarithmic scale and why Google uses no such metric. - [Disavow Links](https://rankosaur.com/en/wiki/disavow-links): When disavowing is genuinely needed, the file format, domain-level entries and the toxic-link myth. ## Optional - [Support & FAQ](https://rankosaur.com/support): Help, frequently asked questions and contact information. - [Privacy Policy](https://rankosaur.com/privacy): How the extension handles data and privacy.