Google's official position since 2023 is clear: they don't care if a human or machine wrote your content, only whether it's useful and meets their quality guidelines. AI-generated content isn't inherently against their policies. The practical limit isn't about the percentage of AI content on your site—it's about execution quality. The real constraints are editorial control and competition. Purely automated AI content without human review usually produces generic material that already exists in hundreds of variations across the web. It ranks poorly not because it's AI-written, but because it adds nothing unique. If your niche has weak competition, lightly edited AI content might rank. In competitive spaces like finance, legal, or B2B SaaS, you need substantial human expertise layered in. At Ottawa SEO, we use AI as a research and drafting tool for roughly 60-70% of content projects, but every piece gets significant human restructuring. That means rewriting the intro based on actual search intent analysis, injecting specific examples or data we've observed, cutting redundant sections AI loves to generate, and ensuring the content answers questions competitors missed. The AI draft saves 40% of the time—the human editing is what makes it rank. Watch out for these AI tells that tank rankings: repetitive phrasing across pages, lack of specific examples, obvious keyword stuffing, and thin answers to complex questions. Google's algorithms have gotten sharp at detecting when content just repackages existing SERPs without adding insight. The acceptable amount is 100% if you're editing it like a senior editor would handle a junior writer's draft. It's 0% if you're publishing raw ChatGPT outputs at scale. The difference isn't the tool—it's whether you're creating something genuinely more useful than what already ranks. Most businesses should think of AI as a force multiplier for subject matter experts, not a replacement for editorial judgment.