DidYouSEO is a search engine optimization auditing and monitoring tool designed to help website owners identify technical issues that may affect their Google rankings and visibility in AI-powered search platforms. The tool provides a prioritized audit of over 30 checks across technical SEO, performance, content, and accessibility categories, with results delivered in under 30 seconds. It also tracks visibility across three AI platforms: ChatGPT, Gemini, and Perplexity. The service offers 29 free tools that require no sign-up or credit card, and the first site audit is free. Key features include keyword research, on-page SEO analysis, technical audits, rank tracking, and AI visibility monitoring. The audit system identifies specific issues such as uncompressed JavaScript assets, slow Largest Contentful Paint (LCP) times, missing alt text on images, pages without meta descriptions, and canonical mismatches on paginated routes. Each finding is categorized by severity, labeled as critical, warning, or notice, and ranked by the impact it may have on traffic. The tool also integrates with Google Search Console to show real ranking data and tracks competitor activity, including keywords that competitors are likely to target. Typical use cases involve website owners or SEO practitioners running an initial audit to discover technical problems, then using the prioritized list to address the most impactful issues first. The workflow begins with a free site audit, after which users can access additional features based on their subscription tier. Paid plans offer up to five registered sites, security and accessibility audits, weekly score monitoring, PDF and Markdown export, and higher page credits per month. The starter plan includes one registered site and up to ten pages per audit. The tool is accessible via the web at didyouseo.com.