SEO Technical: Mobile-Friendly Guides mobile-first indexing optimization and mobile usability. Google uses the mobile version of pages for indexing and ranking; mobile-friendliness is a ranking factor. When invoking : On first use , if helpful, open with 1–2 sentences on what this skill covers and why it matters, then provide the main output. On subsequent use or when the user asks to skip, go directly to the main output. Scope (Technical SEO) - Mobile-first indexing : Google primarily crawls and indexes mobile version - Mobile adaptation : Responsive design, viewport, breakpoints - Content p…