SEO tools aren't just for marketers tracking keyword positions. Engineers use them to diagnose [technical problems](/resources/app-developer/what-is-seo-for-app-developer) that kill rankings: crawl inefficiencies, broken redirects, schema parsing errors, and performance bottlenecks.
The core insight: Google sees your site as a web crawler would. That means redirect chains that look fine in your browser create crawl waste. JavaScript rendering issues hide content from indexation. Core Web Vitals thresholds directly affect ranking eligibility.
A crawl audit reveals exactly what Googlebot encounters—not what your users see. Schema validators catch structured data mistakes that prevent rich results. Log file analyzers show whether Google's actually crawling your most important pages or wasting quota on thin content.
Developers who understand SEO tooling make better architectural decisions: cleaner URL structures, faster first-paint rendering, proper rel-canonical implementation. The tools themselves don't fix anything. They expose the problems your code creates or inherits.