Technical SEO Issues — Common Problems and How to Fix Them

Technical SEO problems are among the most common reasons websites underperform in organic search — and among the most overlooked. Unlike content or link issues, technical problems are often invisible to the naked eye. A page can look perfectly normal to a visitor while being partially or entirely inaccessible to search engines.

This guide covers the most common technical SEO issues, what causes them, and what fixing them looks like in practice. If you want to work through these systematically, the technical SEO checklist is a useful companion.

Crawlability problems

Crawlability issues prevent search engines from accessing pages in the first place. They are often caused by mistakes in robots.txt configuration, incorrect use of noindex directives, or pages that have no internal links pointing to them and are therefore invisible to crawlers.

The most common crawlability problems are:

  • Pages blocked by robots.txt that should be accessible — a particularly easy mistake to make during site migrations or development freezes where staging configurations carry over to production
  • Noindex tags applied site-wide or to the wrong pages — sometimes introduced by a plugin or CMS setting rather than deliberate decision
  • Orphan pages — pages that exist but have no internal links pointing to them, meaning crawlers have no path to discover them
  • Redirect chains — where page A redirects to page B which redirects to page C, wasting crawl budget and diluting link equity with every hop

The starting point for diagnosing crawlability issues is Google Search Console’s Coverage report, combined with a crawl of the site using a tool like Screaming Frog or Sitebulb. Log file analysis is the most precise method — it shows exactly which pages Googlebot is visiting, how often, and what response codes it is receiving.

If your pages are not being indexed despite appearing crawlable, see the guide on Google not indexing pages for a more detailed breakdown.

Indexing issues

Indexing issues occur when pages are crawled but not added to Google’s index — or are indexed in a way that prevents them from ranking. This is distinct from crawlability: a page can be crawled but excluded from the index for a number of reasons.

Common indexing problems include:

  • Duplicate content — multiple URLs serving the same or very similar content, causing Google to choose one version to index and ignore or devalue the others
  • Canonical tag errors — pointing to the wrong URL, creating self-referencing canonicals where they are not needed, or failing to implement canonicals where they are
  • Thin content — pages with very little substantive content that Google judges as providing insufficient value to include in the index
  • Soft 404s — pages that return a 200 status code to crawlers but show an error or empty state to users, confusing search engines about whether the page is valid
  • Hreflang errors on international sites — incorrect or missing language and region tags that cause indexing conflicts between versions of the same content

Google Search Console’s URL Inspection tool is the most direct way to check the indexed status of individual pages and understand why a page may have been excluded.

Site architecture problems

Site architecture affects how efficiently search engines can crawl a site, how authority flows between pages, and how clearly Google understands the relationship between different sections of content. Poor architecture is one of the most structurally damaging technical SEO issues because it affects the entire site rather than individual pages.

The most common architecture problems are:

  • Important pages buried too deep — if a key page requires six or seven clicks to reach from the homepage, it will receive less crawl attention and fewer internal links than it should
  • Flat or inconsistent URL structures — URLs that do not reflect the logical hierarchy of the site make it harder for search engines to understand topical relationships
  • Poor internal linking — high-value pages that receive few or no internal links miss out on the authority signals that would help them rank
  • Pagination issues — improperly handled paginated series can result in crawl budget being wasted on pagination pages rather than the content itself

Architecture issues require a site-wide view rather than a page-by-page fix. A structured crawl analysis, combined with a review of internal link distribution, is the best starting point. See the guide on SEO site architecture for more in-depth info.

Page speed and Core Web Vitals failures

Google’s Core Web Vitals — Largest Contentful Paint (LCP), Cumulative Layout Shift (CLS), and Interaction to Next Paint (INP) — are the primary framework for measuring page experience. Failing these thresholds is not a guaranteed ranking penalty, but in competitive SERPs where other signals are similar, it can be a meaningful disadvantage.

The most common causes of Core Web Vitals failures are:

  • Unoptimised images — large image files that are not compressed or served in modern formats like WebP, causing slow LCP times
  • Render-blocking resources — JavaScript or CSS files that prevent the browser from rendering the page until they have fully loaded
  • Third-party scripts — analytics, chat widgets, advertising tags, and tracking pixels that add significant load time and can cause layout shifts
  • Poor server response times — slow TTFB (Time to First Byte) caused by inadequate hosting, unoptimised databases, or lack of caching

Google Search Console’s Core Web Vitals report provides a site-wide view of which pages are failing and to what degree. PageSpeed Insights gives page-level diagnostics with specific recommendations.

For a deeper look at this topic, see the guide on site speed optimisation and Core Web Vitals.

JavaScript rendering problems

JavaScript SEO issues are among the most technically complex problems to diagnose. They occur when important content, internal links, or metadata are rendered via JavaScript in a way that Googlebot cannot reliably access or process.

Symptoms of JavaScript rendering problems include pages that appear blank or incomplete in Google’s cached version, internal links that are not being followed by crawlers, or content that is visible to users but absent from the indexed version of the page. These issues are most common on React, Angular, and Vue-based sites, and on any site that relies heavily on client-side rendering.

Diagnosing rendering issues requires comparing what Googlebot sees against what a browser renders — using Google Search Console’s URL Inspection tool, the Fetch and Render function, and in more complex cases, dedicated rendering analysis tools.

Structured data errors

Structured data (schema markup) is the code that makes pages eligible for rich results in Google Search — star ratings, FAQ dropdowns, event listings, product prices, and similar enhanced SERP features. Errors in structured data prevent rich results from appearing, which can meaningfully reduce click-through rates.

Common structured data issues include invalid markup that fails Google’s validation requirements, schema types that are present but do not match the actual page content, and outdated markup that references deprecated schema properties. Google’s Rich Results Test and Search Console’s Enhancement reports are the primary tools for identifying and resolving these errors.

How to approach fixing technical SEO issues

Not all technical SEO issues have equal impact, and trying to fix everything simultaneously is rarely the right approach. A structured audit identifies all issues, but prioritisation determines what actually gets done — and in what order.

Issues that affect crawlability and indexation should generally be addressed first, since they prevent pages from appearing in search results at all. Architecture and internal linking issues come next, as they affect authority distribution across the site. Speed and structured data improvements follow, as they affect how pages perform once they are already ranking.

If you need a systematic starting point, the technical SEO checklist covers the most critical elements in priority order. For a complete picture of what is holding your specific site back, a technical SEO audit provides a structured analysis with clear, prioritised recommendations. Or try the technical SEO priority scorer to swiftly check which issues apply to your site and get a prioritised action list in minutes.

For ongoing support with identifying and fixing technical SEO issues, find out more about my technical SEO services.

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