On-page SEO factors are any elements you can optimize directly within your website's HTML and content. The most impactful ones include your title tag (the clickable headline in search results), meta description (the snippet text below it), and header hierarchy (H1 through H6 tags that structure your content). Beyond metadata, your actual content matters most—Google evaluates topical relevance, keyword placement in natural language, content depth, and whether you answer the searcher's intent better than competing pages. Technical on-page factors carry significant weight too. URL structure should be clean and descriptive (example.com/seo-services beats example.com/page?id=123). Image optimization includes compressive file sizes, descriptive filenames, and alt text that serves accessibility and keyword relevance. Internal linking distributes authority across your site and helps Google understand your content relationships. Page speed—measured by Core Web Vitals like LCP, FID, and CLS—directly impacts rankings since 2021, especially on mobile. Schema markup is an underused on-page factor. Adding structured data for FAQs, local business details, or product info can earn rich snippets in search results, dramatically improving click-through rates even without ranking higher. At Ottawa SEO, we've seen local service pages jump from 2% to 8% CTR after implementing LocalBusiness schema properly. Mobile responsiveness isn't optional anymore—it's been a ranking factor since Google's mobile-first indexing rollout finished in 2023. Your site must render correctly on all devices, with touch targets sized appropriately and text readable without zooming. Content structure matters here too: short paragraphs, bullet points, and clear subheadings make mobile reading tolerable. The mistake most site owners make is over-optimizing one factor while ignoring others. A perfect title tag won't save a page that loads in 8 seconds or has 150 words of thin content. We prioritize based on current deficits—if your content is strong but technical performance is poor, Core Web Vitals work delivers faster ROI than rewriting pages that already rank decently.