We Audited 20+ Sites for AI Visibility. Here Are the Most Common Mistakes

Most sites we reviewed had decent technical foundations. Good Core Web Vitals, clean sitemaps, well-structured URLs. They ranked fine in Google. But when you queried their niche in ChatGPT, Perplexity, or Gemini - nothing. Completely absent. That's the AI visibility gap. After 20+ audits, the pattern is consistent. The same mistakes appear across industries, site sizes, and tech stacks. Here's what we actually found, ordered by how often we see it. Mistake #1: Blocking AI Crawlers in robots.txt This is the fastest way to disappear from AI search. You can't be cited if the crawler can't read your content. Check your robots.txt file right now: User-agent: GPTBot Disallow: / User-agent: ClaudeBot Disallow: / User-agent: ChatGPT-User Disallow: / User-agent: Google-Extended Disallow: / User-agent: PerplexityBot Disallow: / If any of those blocks exist - you're opted out. In many sites we audited, these were added automatically by security plugins or firewall rules. Nobody noticed. An import