We break down the most common technical SEO mistakes and explain how to detect and fix them
Why Is Technical SEO Critical?
Even the best content won't help if search crawlers can't properly index your site. Technical SEO is the foundation without which all other efforts are wasted.
Mistake 1: Slow TTFB and Core Web Vitals
Google officially uses Core Web Vitals as a ranking factor. LCP over 2.5 seconds, FID over 100ms, or CLS over 0.1 directly hurts your rankings.
Mistake 2: Missing or Incorrect Canonical Tags
Duplicate pages dilute "SEO value." Every page should have a correct canonical pointing to the primary version.
Mistake 3: Incorrect robots.txt
Blocking access to important resources (CSS, JS) or entire site sections is a common mistake. Review your robots.txt regularly.
Mistake 4: Broken Links (404 Errors)
A high percentage of 404 errors hurts UX and wastes crawl budget. Regular audits with Screaming Frog are a must.
Mistake 5: Missing or Incorrect sitemap.xml
A sitemap helps Google find all important pages. It should be current and exclude noindex pages.
Mistake 6: Client-Side Rendering for Critical Content
If main content is rendered only in the browser (React/Vue SPA without SSR), Google may not index it promptly or completely.
Mistake 7: Missing hreflang for Multilingual Sites
For sites in multiple languages, hreflang tells Google which version to show to the relevant audience. Without it — duplicates and incorrect geotargeting.