Technical SEO Audit: What to Check Beyond Content

Your content can be brilliant. Your keywords can be perfectly researched. None of that matters if Google cannot crawl your site, index your pages, or render your content properly.

Technical SEO is the foundation everything else sits on. Get it wrong and you are invisible. Get it right and every piece of content you publish has a fighting chance at ranking.

This is a complete technical SEO audit checklist that goes beyond the basics most guides recycle. We are covering the specific checks, the exact things to look for, and the honest truth about which issues actually matter for your site. If you want the full picture of SEO auditing, including AI-powered approaches, start with our complete AI SEO audit guide.

1. Crawlability: Can Google Actually Reach Your Pages?

Before Google can rank a page, it has to find it. Crawlability is about making sure nothing is blocking Googlebot from discovering and accessing your content.

Robots.txt

Your robots.txt file sits at the root of your domain and tells crawlers which URLs they can and cannot access. It is the first thing Googlebot checks, and mistakes here can silently block your entire site. Google's official robots.txt documentation covers the full specification if you want to understand every directive.

What to check:

• Make sure your robots.txt exists and returns a 200 status code. A 404 or 500 means Google treats it as if there are no restrictions, which sounds fine until you realize you have no control.
• Check that you are not accidentally blocking important directories. A common mistake: blocking /api/ paths that serve rendered content for JavaScript-heavy pages.
• Verify your sitemap URL is referenced in robots.txt with a Sitemap: directive.
• Look for overly broad Disallow rules. Something like Disallow: / on a staging environment that accidentally went to production will kill your traffic overnight.

# Example: clean robots.txt
User-agent: *
Disallow: /admin/
Disallow: /cart/
Disallow: /checkout/
Disallow: /search?

Sitemap: https://example.com/sitemap.xml

XML Sitemaps

An XML sitemap is a list of URLs you want Google to know about. It does not guarantee indexation, but it helps Google discover pages faster, especially on large or new sites. Google's sitemaps documentation explains the full format and best practices.

What to check:

• Every URL in your sitemap should return a 200 status code. Sitemaps full of 404s or 301s signal a poorly maintained site.
• The sitemap should not include pages you have noindex on. That is a contradiction: you are telling Google "here is a page" and "do not index this page" at the same time.
• If your site has more than 50,000 URLs, split into multiple sitemaps with a sitemap index file.
• Check lastmod dates. If every page shows the same date, Google may stop trusting your sitemap timestamps entirely.

Crawl Budget: The Overhyped Concern

Most sites do not need to worry about crawl budget. Unless you have 10,000+ pages, Google will crawl everything. This is one of those topics that SEO consultants love to bring up because it sounds technical and important, but for the average site with a few hundred pages, it is a non-issue.

Where crawl budget actually matters: large e-commerce sites with faceted navigation generating millions of URL combinations, news sites publishing hundreds of articles daily, or sites with massive parameter-based URL variations. If that is you, focus on removing low-value URLs from crawl paths, using canonical tags correctly, and pruning thin content.

2. Indexation: Getting Pages Into (and Out of) the Index

A page can be crawlable but still not indexed. Indexation issues are some of the trickiest technical SEO problems because the symptoms are subtle. Your page exists, Google can reach it, but it simply does not show up in search results.

Canonical Tags

The rel="canonical" tag tells Google which version of a page is the "real" one. It is critical for handling duplicate content, and getting it wrong can make entire sections of your site disappear from search results.

What to check:

• Every page should have a self-referencing canonical tag pointing to its own URL. If it is missing, Google guesses which version to index.
• Canonical URLs should match the protocol (HTTPS, not HTTP) and the trailing slash convention you use across the site.
• Watch for pages where the canonical points to a completely different page. This can happen with pagination, filtering, or CMS plugins that auto-generate canonicals incorrectly.
• Check that your canonical URLs are not pointing to noindex pages. That combination confuses Google.

For more on how to set up your meta tags correctly, including canonical tags, see our meta tags for SEO guide.

The Index Coverage Report

Google Search Console's Pages report (formerly Index Coverage) is your best friend here. Look at these specific things:

• "Crawled, currently not indexed" means Google found the page but decided not to index it. This usually indicates thin content or quality issues.
• "Discovered, currently not indexed" means Google knows the URL exists but has not bothered crawling it yet. This is where crawl budget actually matters.
• "Excluded by noindex tag" should only show pages you intentionally excluded. If important pages appear here, someone added a noindex tag by mistake.
• "Duplicate without user-selected canonical" means Google found duplicates and chose which one to index on its own. Check if it picked the right one.

Noindex and Nofollow

Use noindex to keep pages out of search results (thank you pages, internal search results, admin pages). Use nofollow on links you do not want to pass authority through. But be careful: adding noindex to a page does not prevent it from being crawled. It just prevents it from appearing in results. If you want to save crawl budget, use robots.txt instead.

3. HTTPS, Redirects, and URL Hygiene

These are the plumbing of your website. Unsexy, but absolutely critical.

HTTPS

In 2026, there is no excuse for not running HTTPS. It has been a confirmed ranking signal since 2014. What most people miss is not the certificate itself, but the implementation details.

What to check:

• Your SSL certificate is valid and not expiring within 30 days.
• All HTTP URLs redirect to HTTPS with a 301, not a 302.
• No mixed content warnings. This happens when your page loads over HTTPS but includes images, scripts, or stylesheets over HTTP. Modern browsers will block the HTTP resources, breaking your page.
• Your HSTS header is set with a long max-age (at least 1 year) to prevent downgrade attacks.

Redirect Chains and Loops

A redirect chain is when URL A redirects to URL B, which redirects to URL C. Each hop loses a small amount of link equity, and chains longer than three hops can cause Googlebot to give up entirely.

What to check:

• No redirect chains longer than two hops. If you find them, update the first redirect to point directly to the final destination.
• No redirect loops (A redirects to B, B redirects to A). These will crash crawlers and browsers alike.
• All redirects are 301 (permanent), not 302 (temporary), unless the redirect really is temporary. Using 302s for permanent moves means Google may keep the old URL in the index indefinitely.

404 Errors

A few 404s are normal. Pages get deleted, URLs change. The problem is when important pages return 404s, or when you have thousands of them creating a poor user experience.

What to check:

• Check Google Search Console for 404 errors. Focus on pages that had traffic or backlinks.
• Set up 301 redirects for deleted pages that still receive traffic.
• Make sure your custom 404 page is helpful: include a search bar, links to popular pages, and a clear way back to the homepage.
• Check that your 404 page actually returns a 404 status code. Some CMS setups serve a "Page not found" message with a 200 status code (a "soft 404"), which confuses Google.

URL hygiene ties directly into your on-page SEO checklist too. Clean URLs, consistent formatting, and proper redirects form the backbone of both technical and on-page SEO.

4. Site Speed and Core Web Vitals

Page speed is a ranking factor, and since 2021, Google has been measuring it through Core Web Vitals. The three metrics that matter:

• Largest Contentful Paint (LCP): How fast the main content loads. Target: under 2.5 seconds.
• Interaction to Next Paint (INP): How quickly the page responds when a user interacts with it. Target: under 200 milliseconds.
• Cumulative Layout Shift (CLS): How much the page layout jumps around while loading. Target: under 0.1.

What to check:

• Run your key pages through Google PageSpeed Insights. Do not just check the homepage. Check category pages, product pages, and blog posts too.
• Look at field data (real user metrics), not just lab data. Lab data shows what could happen. Field data shows what actually happens for your users.
• Common LCP killers: unoptimized hero images, render-blocking CSS/JS, slow server response times (TTFB over 800ms).
• Common CLS culprits: images without width/height attributes, ads that inject without reserved space, fonts that cause layout shifts when they load.
• Check for excessive JavaScript. If your page loads 2MB of JS just to display a blog post, you have a problem that no amount of optimization can hide.

5. Mobile-Friendliness and Responsive Design

Google uses mobile-first indexing, which means it primarily uses the mobile version of your content for indexing and ranking. If your mobile experience is broken, your desktop rankings suffer too.

What to check:

• Your site uses responsive design, not a separate mobile domain (m.example.com). If you are still on a separate mobile domain, migrating to responsive should be a top priority.
• All content visible on desktop is also visible on mobile. Do not hide content behind "read more" toggles unless you absolutely must. Google will index the hidden content, but it may weigh it less.
• Text is readable without zooming. The minimum font size Google recommends is 16px.
• Tap targets (buttons, links) are at least 48x48 pixels and have enough spacing between them. Fat-finger taps on tiny links create a terrible experience.
• No horizontal scrolling. If users have to scroll sideways on mobile, your responsive design is broken.
• Check that viewport meta tag is set correctly: <meta name="viewport" content="width=device-width, initial-scale=1.0">

For a deeper look at mobile optimization and what it means for your rankings, read our mobile SEO guide.

6. Structured Data Validation

Structured data (Schema.org markup, typically implemented as JSON-LD) helps Google understand your content and can unlock rich results like star ratings, FAQ dropdowns, recipe cards, and product listings.

What to check:

• Run your pages through Google's Rich Results Test to verify your markup is valid and eligible for rich results.
• Check for required properties. Each schema type has mandatory fields. An Article schema without headline or datePublished will not generate rich results.
• Make sure the structured data matches the visible content. If your JSON-LD says the product costs $50 but the page shows $75, Google may issue a manual action for misleading structured data.
• Do not mark up content that is not on the page. This includes adding FAQ schema for questions that do not appear in the visible content.
• Check Search Console's Enhancements reports for structured data errors and warnings. These are often the first sign of markup issues.

Common schema types to implement:

• Organization: For your homepage. Includes logo, social profiles, contact info.
• Article/BlogPosting: For blog posts. Enables article-specific rich results.
• Product: For e-commerce product pages. Shows price, availability, reviews.
• FAQ: For pages with frequently asked questions. Can get accordion-style results.
• BreadcrumbList: For site navigation. Shows breadcrumb trail in search results.

Internal linking and structured data work together here. A clear site architecture with proper internal links gives Google the context it needs, and structured data makes that context explicit and machine-readable.

7. Hreflang and International SEO

If your site serves content in multiple languages or targets multiple countries, hreflang tags tell Google which version to show to which audience. If you only operate in one language and one country, you can skip this section entirely.

What to check:

• Every page in a language group references all other versions, including itself. If your English page links to the French version, the French version must link back to the English version. Missing return tags are the most common hreflang error.
• Use correct language and country codes. It is en-US, not en-us or eng-US. The language code is ISO 639-1, the country code is ISO 3166-1 Alpha 2.
• Include an x-default hreflang for users who do not match any of your specified language/country combinations.
• Canonical tags and hreflang tags should not contradict each other. If the English page canonicalizes to itself, the French page should also canonicalize to itself, not to the English version.
• For large sites, implement hreflang via XML sitemaps rather than HTML tags. It is easier to maintain and less likely to have errors.

<!-- Example: hreflang implementation -->
<link rel="alternate" hreflang="en-US" href="https://example.com/page" />
<link rel="alternate" hreflang="fr-FR" href="https://example.com/fr/page" />
<link rel="alternate" hreflang="x-default" href="https://example.com/page" />

Putting Your Technical SEO Audit Together

Running through this checklist manually is possible, but it takes time. Here is a practical approach:

1. Start with Google Search Console. The Pages report, Core Web Vitals report, and Enhancement reports give you the issues Google already knows about. Fix those first.
2. Crawl your own site. Use a tool like Screaming Frog (free up to 500 URLs) or OwnVector to find redirect chains, broken links, missing canonicals, and other structural issues.
3. Prioritize by impact. A noindex tag on your most important product page is more urgent than a missing hreflang tag on a low-traffic blog post. Focus on pages that drive revenue or traffic first.
4. Document everything. Track what you found, what you fixed, and when. Technical SEO issues have a way of creeping back, especially after CMS updates or redesigns.
5. Set up monitoring. Do not wait for quarterly audits to catch problems. Set up alerts in Search Console for crawl errors and drops in indexed pages.

The reality is that most sites have the same handful of technical issues: missing canonicals, redirect chains from old migrations, images without proper sizing, and a few pages accidentally blocked by robots.txt. Find those, fix them, and you have already handled 80% of what a technical audit would uncover.