Diagnose SEO Structured diagnostic framework for crawl issues, canonicalization errors, indexation problems, and rendering failures. Diagnostic Approach Technical SEO problems fall into four categories. Diagnose in this order — each layer depends on the previous one working correctly: 1. Crawlability — Can search engines find and access the pages? 2. Indexability — Are the pages allowed to be indexed? 3. Renderability — Can search engines see the full content? 4. Signals — Are the right signals (titles, structured data, links) in place? Layer 1: Crawlability Check these in order: robots.txt -…