Accessibility
Optimal use of robots directives e.g. meta robots, robots.txt, XML sitemaps
Relevant and accessible architecture: Main and sub navigation, internal linking, orphaned content, systematic duplication, crawl maps, facets, breadcrumbs, URL structure
Content accessibility and attribution: hreflang (language variants), canonical use (self-referential, cross-domain or other), pagination, infinite scroll, image alt (for both accessibility and relevance), rendering issues
Resource based: accessibility, linked to 3xx’s, 4xx errors and handling, redirect chains, cache control / modified, resource delivery
Console errors: Soft 404 detection, performance issues, crawl stats and errors, HTML errors, sitemaps
Log file analysis: understanding crawl behaviour and efficiency
and More
