Quick answer
A technical SEO audit should check crawl access in robots.txt and server responses, indexing status in Search Console, accidental noindex or canonical errors, duplicate and thin pages, XML sitemaps, redirects and broken links, JavaScript rendering of important content, Core Web Vitals and mobile usability, HTTPS, structured data validity, internal linking and site architecture, and international or local settings where relevant.
Key takeaways
- Start with Search Console indexing and crawl reports.
- Canonical, noindex and redirect mistakes often cause hidden losses.
- Important content should be present in rendered and ideally initial HTML.
- Prioritize fixes by affected traffic and business value.
Who this guide is for
Website owners, marketing managers and developers who need a structured way to find technical issues limiting search visibility.
Check crawl access
Review robots.txt to make sure important sections are not blocked and that it is not blocking resources needed to render pages, such as CSS and JavaScript. Check that servers return correct status codes: 200 for live pages, 301 or 308 for permanent redirects, 404 or 410 for removed pages, and no soft 404s that return 200 for missing content. Look at crawl stats in Search Console for errors, slow responses and unexpected crawler blocks from firewalls or CDNs.
Review indexing
Use Search Console’s page indexing report to see which pages are indexed and why others are not: crawled but not indexed, duplicate without user-selected canonical, blocked by noindex, alternate page with proper canonical and so on. Inspect important URLs individually. Look for valuable pages excluded unexpectedly, and for low-value pages indexed unnecessarily, such as internal search results, tag archives or staging environments.
Fix duplication and canonicals
Duplicate content arises from URL parameters, HTTP and HTTPS or www and non-www variants, trailing slashes, printer versions and near-identical location or product pages. Choose one canonical URL per piece of content, redirect variants where possible and use rel=canonical consistently. Make sure canonicals point to indexable pages that return 200, and that sitemaps list only canonical URLs.
Check rendering and JavaScript
If your site relies on JavaScript frameworks, use the URL Inspection tool to view rendered HTML and confirm important text, links and metadata are present. Google can render JavaScript, but rendering may be delayed, and some other crawlers, including several AI crawlers, may not execute it fully. Server-side rendering, static generation or prerendered snapshots make content reliably available. Avoid links that work only through click handlers instead of real anchor tags with href attributes.
Assess speed and mobile usability
Review Core Web Vitals in Search Console and page-level diagnostics in PageSpeed Insights. Check templates for large images, render-blocking scripts and layout shifts. Google uses mobile-first indexing, so the mobile version must contain the same important content, structured data and metadata as desktop. Test key templates on real devices.
Validate metadata, structured data and links
Check that each indexable page has a unique, descriptive title and meta description, one clear H1 and logical headings. Validate structured data and fix errors in Search Console enhancement reports. Crawl the site with an SEO crawler to find broken internal links, redirect chains, orphan pages with no internal links and important pages buried many clicks deep. Strengthen internal links to priority pages.
Prioritize and verify fixes
Rank issues by the traffic and business value of affected pages and the effort to fix. Template-level issues often affect hundreds of pages and deserve priority. After fixes, request reindexing for key URLs, monitor indexing reports and track performance. Schedule lighter audits after major releases or migrations, since many technical SEO problems are introduced by unrelated website changes.
Scope checklist
- Are important sections crawlable and returning correct status codes?
- Which valuable pages are excluded from the index, and why?
- Are canonicals and sitemaps consistent?
- Is important content present in rendered HTML?
- Are issues prioritized by business impact?
Frequently asked questions
How often should I do a technical SEO audit?
A thorough audit annually and lighter checks after major releases, redesigns or migrations work for many sites. Monitor Search Console continuously for sudden issues.
What tools do I need for a technical SEO audit?
Google Search Console, PageSpeed Insights, a site crawler such as Screaming Frog or Sitebulb, and browser developer tools cover most needs.
Can JavaScript websites rank well on Google?
Yes, if important content and links are rendered reliably. Server-side rendering or prerendering reduces risk, especially for crawlers that do not execute JavaScript.
Sources and implementation references
- Google Search Central: page indexing report
Explanation of indexing statuses in Search Console.
- Google Search Central: consolidate duplicate URLs
Canonicalization methods and best practices.
- Google Search Central: JavaScript SEO basics
How Google processes JavaScript sites.
Prepared with AI assistance as an engineering decision guide. Examples are illustrative unless explicitly labelled as an internal implementation. No independent expert review or customer outcome is claimed.
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