Technical SEO Audit Checklist Covering 47 Issues That Can Hurt Your Rankings

Your website can have great content and still lose rankings. The cause is often hidden in the technical layer of your site. Search engines need to crawl your pages and read them clearly. They also need your site to load fast on every device. When one of these breaks your rankings can slip without warning.

Most site owners only look at content and keywords. They skip the technical side. A broken redirect or a missing tag looks small on its own. Add a few of them to slow pages and your traffic can drop quietly over months.

AI search adds one more layer. ChatGPT search, Perplexity and Google AI Overviews need to reach and read your pages before they can quote them.

This guide covers 47 technical SEO issues in simple groups. For each one you get what goes wrong, how to check it and how to fix it. You also get the tools you need, the order to run your audit and a simple way to decide what to fix first.

What Is A Technical SEO Audit?

A technical SEO audit is a check of how well search engines and AI crawlers can find, render, index and understand your website. It looks at crawling, speed, mobile setup, structured data, security and duplicate pages. It does not cover content writing or backlinks.

Technical SEO Audit Vs Other SEO Audits

• Technical audit: Can search engines reach, render and index your pages?

• On-page audit: Do titles, headings and content match the right search terms?

• Off-page audit: Are backlinks and brand mentions building trust?

Working from a fixed technical SEO audit checklist keeps every audit consistent. You test the same points in the same order so nothing gets missed between audits.

Tools You Need Before You Start

You can run most of this audit with free tools. A paid crawler saves time on bigger sites.

Free And Paid Technical SEO Audit Tools

• Google Search Console: Pages report, URL Inspection, robots.txt report, Core Web Vitals, Manual actions and Security issues

• Bing Webmaster Tools: Shows how Bing crawls your site. Bing's index also powers Microsoft Copilot and feeds other AI search tools

• A site crawler: Screaming Frog or Sitebulb crawls every URL the way a search bot does

• PageSpeed Insights and Lighthouse: Real user speed data plus lab tests

• Rich Results Test and Schema Markup Validator: Find structured data errors

• Server log files: Show which pages Googlebot and AI bots actually visit

For a fast first look at one page try our free SEO page audit tool. It checks titles, headings, canonicals, alt text, schema and indexability in one go.

Crawlability And Indexing Issues

Search engines can only rank pages they can find and read. If crawling is blocked or confused your best pages may never show up in search results.

Common Crawlability Problems To Check

1. Robots.txt blocking important pages or files. One wrong Disallow line can hide a whole folder from Google.

   • Check: Open the robots.txt report in Search Console. Test key URLs with URL Inspection.

   • Fix: Allow every page you want ranked. Don't block the CSS or JavaScript files your pages need to display.

2. Noindex left on live pages. This often happens when a staging site goes live with its settings still on.

   • Check: Crawl the site and look for noindex in meta robots tags and in X-Robots-Tag HTTP headers.

   • Fix: Remove noindex from every page you want in search results.

3. XML sitemap errors. A sitemap full of redirects or dead pages sends mixed signals.

   • Check: Compare submitted and indexed pages in the Sitemaps report. Crawl the sitemap URLs to find non-200 pages.

   • Fix: List only live canonical pages and update the file automatically. Our guide on creating and submitting an XML sitemap walks through the setup.

4. Orphan pages. Pages with no internal links get crawled less and rarely rank.

   • Check: Compare your crawl list with sitemap and analytics URLs. Pages the crawler never reached are orphans.

   • Fix: Link to them from related pages. Remove them if they add no value.

5. Crawl budget wasted on junk URLs. Filters, sort options, internal search pages and session IDs can create thousands of useless URLs. For example a shoe store with size, colour and price filters can turn 500 products into tens of thousands of crawlable pages.

   • Check: Look for parameter URLs in your crawl and in the Crawl stats report.

   • Fix: Block internal search results in robots.txt. Point filter variations to the main category with canonical tags.

6. Soft 404 pages. The page says "not found" or shows nothing but the server still returns a 200 status.

   • Check: Look for Soft 404 in the Search Console Pages report.

   • Fix: Return a real 404 or 410 for removed pages. Use a 301 redirect only when a close replacement exists.

Rendering And JavaScript Issues

Many modern sites build pages with JavaScript. Google can render it but that takes extra time. Most AI crawlers tested so far don't run JavaScript at all so they only see your raw HTML.

JavaScript Problems To Check

1. Key content only appears after JavaScript runs.

   • Check: Compare view source with the rendered HTML in URL Inspection. Look for missing text, links, titles or canonical tags.

   • Fix: Use server-side rendering or static generation for important pages. Frameworks like Next.js support both.

2. Links that are not real links. Buttons and onclick events can't be followed by crawlers.

   • Check: Crawl once with JavaScript rendering on and once with it off. Compare how many links each crawl finds.

   • Fix: Use normal <a href> links for all navigation.

3. Content that loads only after a click or scroll. Bots don't click buttons or scroll to load more items.

   • Check: Search the rendered HTML in URL Inspection for text that sits behind "load more" buttons or infinite scroll.

   • Fix: Put important content in the first HTML load. Give paginated lists their own crawlable URLs.

Google also updated its JavaScript documentation in December 2025. Pages that return a non-200 status code may skip rendering completely. Your real pages must return 200 and your error pages should return a proper error code.

Site Architecture And URL Structure Issues

A clear structure helps visitors and search engines understand which pages matter most.

URL And Structure Problems To Fix

1. Messy URLs. Long URLs with random IDs and stacked parameters are hard to read and share.

   • Check: Sort crawled URLs by length and look for parameter-heavy patterns.

   • Fix: Use short lowercase URLs with hyphens between words. Add 301 redirects when you change an old URL.

2. Deep click depth. Pages five or six clicks from the homepage get crawled less often.

   • Check: Open the crawl depth report in your crawler.

   • Fix: Keep important pages within three clicks. Use category hubs, breadcrumbs and related links.

3. Broken internal links. Every link to a dead page wastes crawl time and annoys visitors.

   • Check: Filter your crawl for internal links that return 4xx codes.

   • Fix: Point each link to the correct live page.

4. Vague anchor text. Links that say "click here" or "read more" tell search engines and AI systems nothing.

   • Check: Export internal anchor text from your crawler.

   • Fix: Use short descriptive anchors that name the target topic.

5. Pagination mistakes. Pointing page 2 and page 3 canonicals to page 1 or adding noindex can hide deeper products and posts.

   • Check: Inspect canonical and robots tags on paginated pages.

   • Fix: Give each paginated page a self-referencing canonical and plain crawlable links. Google no longer uses rel next and prev so don't rely on them.

Page Speed And Core Web Vitals Issues

Speed affects rankings and sales. Slow pages lose visitors before they see anything.

Core Web Vitals Thresholds To Aim For

INP replaced First Input Delay as a Core Web Vital in March 2024. Many older checklists still leave it out. Google scores these metrics on real user data so check field data in Search Console before lab tests.

Speed Issues That Hurt Rankings

1. Slow Largest Contentful Paint. The usual causes are a heavy hero image, a slow server or render-blocking files.

   • Check: Run PageSpeed Insights on each main template such as homepage, category, product and blog post.

   • Fix: Compress and preload the hero image. Never lazy load it.

2. Poor Interaction to Next Paint. Heavy JavaScript makes menus and buttons feel stuck.

   • Check: Review INP issues in the Search Console Core Web Vitals report.

   • Fix: Break up long JavaScript tasks. Remove or delay unused scripts and heavy third-party widgets.

3. High Cumulative Layout Shift. Ads, banners and late-loading fonts push content around.

   • Check: Look at the CLS score in PageSpeed Insights and the layout shift markers in Chrome DevTools.

   • Fix: Set width and height on images and videos. Reserve space for ads and embeds.

4. Heavy images. Large uncompressed images are one of the most common causes of slow pages.

   • Check: Sort crawled images by file size.

   • Fix: Use WebP or AVIF formats. Resize images to their display size. Lazy load images below the fold.

5. Render-blocking and third-party scripts. Chat widgets, trackers and big CSS files delay the first paint.

   • Check: Review the render-blocking and unused JavaScript warnings in Lighthouse.

   • Fix: Defer non-critical JavaScript. Inline critical CSS. Remove scripts nobody uses.

6. No caching, compression or CDN. Visitors download every file again from a faraway server.

   • Check: Look for cache-control headers and Brotli or Gzip compression in response headers.

   • Fix: Set browser caching for static files. Turn on compression. Serve files through a CDN with HTTP/2 or HTTP/3.

Mobile And Technical Setup Issues

Google uses mobile-first indexing. The mobile version of your page is the one it crawls and ranks.

Mobile Setup Problems To Review

1. Mobile pages missing content. Text, links or schema hidden on mobile may never be seen by Google.

   • Check: Crawl as Googlebot smartphone. Compare mobile and desktop rendered HTML.

   • Fix: Keep the same main content, links, structured data and meta tags on both versions.

2. Layouts not built for small screens. Tiny text, buttons packed too close and a missing viewport tag all hurt mobile users.

   • Check: Test on real phones and run Lighthouse in mobile mode. Google retired its Mobile-Friendly Test in December 2023.

   • Fix: Add <meta name="viewport" content="width=device-width, initial-scale=1">. Use at least 16px body text and bigger tap targets.

3. Intrusive pop-ups. Full-screen pop-ups that cover content hurt page experience.

   • Check: Open key pages on a phone straight from a Google result.

   • Fix: Use small banners instead. Cookie notices and legally required age checks are fine.

If mobile issues keep coming back the template itself may need rebuilding. A mobile first website design and development approach fixes the root cause instead of patching one page at a time.

Structured Data And Schema Markup Issues

Schema markup tells search engines and AI systems what a page is about. It links your content to real entities like your brand, your authors and your products.

Structured Data Gaps To Look For

1. No core schema types. Without markup machines have to guess what your page is.

   • Check: Run key templates through the Rich Results Test and Schema Markup Validator.

   • Fix: Add Organization on the homepage and Article on blog posts. Add Product on product pages and LocalBusiness if you serve a local area. Add BreadcrumbList across the site.

2. Schema that doesn't match the page. Prices or ratings that visitors can't see break Google's guidelines and can lead to manual actions.

   • Check: Compare schema values with what is shown on the page.

   • Fix: Generate schema from the same data that fills the page.

3. Validation errors. Missing required fields can stop rich results from showing.

   • Check: Open the rich result reports in Search Console.

   • Fix: Add the missing fields and click Validate fix.

4. Chasing removed rich results. Google stopped showing FAQ rich results in May 2026. It dropped HowTo rich results in 2023.

   • Check: List every schema type on your site and whether it still produces a search feature.

   • Fix: Put your effort into types that still show results or help entity understanding. FAQ markup can stay but don't expect a visual result from it.

5. Weak entity details. An author written as plain text or a brand with no profile links is harder to connect to real people and companies.

   • Check: Review the author, publisher, sameAs and dateModified fields in your Article schema.

   • Fix: Use a Person object for authors with job title and profile links. Keep dateModified accurate when you update a page.

Clear schema can also help AI Overviews and LLM tools match your content to the right brand and topic.

On Page Technical Elements Issues

Small mistakes in page code can confuse search engines about the topic of a page.

On Page Technical Mistakes

1. Missing, duplicate or cut-off title tags.

   • Check: Filter your crawl for empty titles, duplicates and titles over about 60 characters.

   • Fix: Write one unique title per page with the main topic near the start.

2. Missing or duplicate meta descriptions. Google may rewrite them but a clear one still earns more clicks.

   • Check: Pull empty and duplicate descriptions from your crawl report.

   • Fix: Write a unique summary of about 140 to 160 characters for key pages.

3. Missing, multiple or misused H1 tags. A common template bug wraps the logo in an H1 on every page.

   • Check: Crawl for pages with zero H1 tags or more than one.

   • Fix: Use one H1 that matches the page topic.

4. Images missing alt text. Search engines and screen readers can't see what an image shows.

   • Check: Crawl for images with empty or missing alt attributes.

   • Fix: Describe each useful image in plain words. Leave purely decorative images with empty alt.

5. Thin or near-duplicate template pages. Think tag pages, empty categories and city pages where only the city name changes.

   • Check: Use near-duplicate and word count filters in your crawler.

   • Fix: Merge, improve or noindex pages that add nothing unique.

Security And Server Configuration Issues

Search engines trust safe and stable sites. Security warnings scare visitors away and server errors slow down crawling.

Security And Server Problems To Check

1. Expired SSL or mixed content. An expired certificate on a subdomain that serves images can break pages without anyone noticing.

   • Check: Use our SSL certificate checker to see expiry dates and covered domains. Crawl for HTTP files loading on HTTPS pages.

   • Fix: Turn on auto-renewal. Load every image, script and font over HTTPS.

2. Site versions not redirecting to one. When HTTP, HTTPS, www and non-www all load you split your ranking signals.

   • Check: Type all four versions into a browser or header checker.

   • Fix: Send every version to one HTTPS version with a single 301 redirect.

3. Redirect chains and loops. Each extra hop slows crawling and loses link value.

   • Check: Open the redirect chain report in your crawler.

   • Fix: Point every old URL straight to its final page. Update internal links to the final URL too.

4. 5xx server errors. Repeated server errors make Googlebot crawl your site less.

   • Check: Look for server errors in the Pages report and Crawl stats. Review logs during traffic spikes.

   • Fix: Upgrade hosting, repair failing plugins and set up uptime alerts.

5. Slow server response. A slow Time to First Byte drags down every other speed metric.

   • Check: Test TTFB in PageSpeed Insights and from a few locations.

   • Fix: Aim for 0.8 seconds or less. Use server caching and a CDN and keep your CMS and plugins updated.

Duplicate Content And International SEO Issues

Duplicate pages force search engines to pick a version on their own. It gets harder when you target more than one country or language.

Duplicate And International Issues To Fix

1. Missing or conflicting canonical tags. Canonicals that point to redirects, 404s or unrelated pages get ignored.

   • Check: Compare the user-declared canonical and Google-selected canonical in URL Inspection.

   • Fix: Add a self-referencing canonical to every indexable page. Point print versions and copies to the main page.

2. Faceted navigation and product variant duplicates. Colour, size and sort filters create near-identical pages. Copied manufacturer descriptions add more duplicates.

   • Check: Look for parameter URLs that share the same title in your crawl.

   • Fix: Let only useful filter pages get indexed and canonical the rest to the main category. Write unique copy for top products. Store owners can find more fixes in our guide to ranking a Shopify store higher on Google.

3. Hreflang errors. Missing return tags, wrong language codes and no x-default confuse country targeting.

   • Check: Run the hreflang report in your crawler.

   • Fix: Every language version must list all versions including itself. Use codes like en-us and add an x-default.

4. Geo-IP redirects that trap crawlers. Googlebot crawls mostly from US IP addresses. Forced country redirects can hide your other versions from it.

   • Check: Load each country version through a US VPN and with a Googlebot user agent.

   • Fix: Show a country suggestion banner instead of redirecting automatically.

AI Search And LLM Crawler Readiness Issues

AI tools like ChatGPT search and Perplexity can only cite pages they can reach and read. The same goes for Copilot and Google AI Overviews. Many older audits skip this part.

AI Crawler Problems To Check

1. AI search crawlers blocked by accident. Some CDN and firewall tools now block AI bots by default.

   • Check: Read robots.txt for rules on OAI-SearchBot, GPTBot, PerplexityBot and ClaudeBot. Review bot settings in Cloudflare or your firewall. Look for these bots in your server logs.

   • Fix: Decide bot by bot. Search bots like OAI-SearchBot fetch pages to answer questions. Training bots like GPTBot collect data for models. A common setup allows search bots and makes a separate choice on training bots. Blocking Google-Extended does not remove you from Google Search.

2. Div-heavy HTML with no clear structure. AI systems pull answers more easily from pages with clear sections and headings.

   • Check: View source and look for header, nav, main, article and footer elements with headings in order.

   • Fix: Use semantic HTML and one clean heading order. Put a direct answer in plain text near the top of each section.

3. Site not set up in Bing Webmaster Tools. Bing's index feeds Microsoft Copilot and other AI search tools.

   • Check: Verify your site in Bing Webmaster Tools and review indexed pages.

   • Fix: Submit your sitemap and turn on IndexNow so new and updated pages get picked up fast.

An llms.txt file is optional. No major search engine has confirmed using it so treat it as low priority.

Search Console And Log File Checks

A crawler shows what a bot could see. Search Console and server logs show what Google actually did.

Final Checks Most Audits Miss

1. Manual actions and indexing warnings left unchecked. A penalty or indexing drop can sit unnoticed for months.

   • Check: Open Manual actions and Security issues in Search Console. Review "Crawled – currently not indexed" and "Discovered – currently not indexed" in the Pages report.

   • Fix: Remove the cause and send a reconsideration request for manual actions. Improve or merge pages Google chose not to index.

2. Server logs never reviewed.

   • Check: Pull at least 30 days of logs. Filter for verified Googlebot, Bingbot and AI crawler visits.

   • Fix: Add internal links to important pages bots rarely visit. Cut crawl waste on URLs bots hit far too often.

Checks like these work best on a schedule. Regular website maintenance and security plans help catch new problems between full audits.

How To Run A Technical SEO Audit Step By Step

Run your technical SEO audit checklist in this order. Early steps often explain problems you find later.

The 8 Step Audit Process

1. Set a baseline. Note organic clicks, indexed pages and Core Web Vitals status in Search Console before changing anything.

2. Crawl the full site. Use Googlebot smartphone as the user agent with JavaScript rendering turned on.

3. Check indexing. Compare crawled URLs, sitemap URLs and indexed pages. Big gaps point to crawl or quality problems.

4. Check rendering. Compare raw and rendered HTML on each main template.

5. Test speed by template. Test homepage, category, product, service and blog templates instead of the homepage alone.

6. Review schema and on-page tags. Validate structured data and fix titles, H1 tags and canonicals.

7. Check AI crawler access and logs. Confirm the right bots can reach your pages and see where they spend time.

8. Prioritise, fix and re-crawl. Give each fix an owner. Re-crawl after release to confirm it worked.

How To Prioritise Technical SEO Fixes

Warnings are not equally urgent. Rank each issue by how many pages it affects and whether it blocks crawling or indexing.

Technical SEO Fix Priority Table

• Fix template-level issues before single-page issues because one fix repairs hundreds of URLs

• Ship fixes in small batches and re-check each batch before moving on

• Record the date of every change so you can match it with ranking movement later

Conclusion

Technical SEO needs regular checks. Your site changes with every new page, plugin and redesign. Search engines and AI tools also keep changing how they crawl and read pages.

The 47 issues in this guide cover 11 areas that run from crawling and rendering all the way to AI crawler access and Search Console data. Start with anything that stops pages from being crawled or indexed. Move to rendering and speed on your main templates next. Then work through schema, on-page tags and AI crawler access.

Re-crawl after every batch of fixes. Run through the full technical SEO audit checklist every few months and do a quick check after any big site change.

FAQ

What is a technical SEO audit checklist?

A technical SEO audit checklist is a list of technical checks for your website. It covers crawling, indexing, rendering, speed, mobile setup, structured data, security and duplicate content. Following it in order helps you find the issues that stop pages from ranking in Google and appearing in AI search answers.

How often should you run a technical SEO audit?

Most business sites should run a full audit every three to six months. Large ecommerce and news sites should check monthly. Always run a quick audit after a redesign, CMS change, domain move or big content launch. Weekly Search Console checks catch sudden problems in between.

How long does a technical SEO audit take?

A small site with under 100 pages usually takes a few hours. A site with thousands of pages often takes several days. Very large or JavaScript-heavy sites can take weeks because rendering and log files need deeper review.

What tools do I need for a technical SEO audit?

Start with Google Search Console, Bing Webmaster Tools and PageSpeed Insights. Add a crawler like Screaming Frog or Sitebulb. Use the Rich Results Test and Schema Markup Validator for structured data. Server logs help on larger sites. Most small sites can run a solid audit with free tools.

Which technical SEO issues should I fix first?

Fix anything that blocks crawling or indexing first. That means robots.txt blocks, noindex on live pages, server errors, expired SSL and manual actions. Next fix sitewide template problems like rendering gaps, redirect chains and slow Core Web Vitals. Leave small polish items for last.

What is the difference between crawling, rendering and indexing?

Crawling is when a bot finds and downloads your page. Rendering is when it runs the page code to see the final version. Indexing is when the search engine stores the page so it can appear in results. A page can be crawled and still never get rendered or indexed.

What are good Core Web Vitals scores?

A good Largest Contentful Paint is 2.5 seconds or less. A good Interaction to Next Paint is 200 milliseconds or less. A good Cumulative Layout Shift is 0.1 or less. Google uses real user data and at least 75% of page visits should meet each target.

Can technical SEO issues affect AI search visibility?

Yes. ChatGPT search, Perplexity and Google AI Overviews need to reach and read your pages first. Blocked AI crawlers, JavaScript-only content, slow servers and messy HTML can all keep your pages out of AI answers.

Should I block AI crawlers like GPTBot?

It depends on your goals. GPTBot collects training data while OAI-SearchBot fetches pages for ChatGPT search answers. A common setup allows search bots so your pages can still be cited and makes a separate decision on training bots. Check your CDN too since some block AI bots by default.

Is FAQ schema still worth adding in 2026?

FAQ schema no longer creates rich results in Google Search. Google removed that feature in May 2026. The markup does no harm and still labels question and answer content clearly. Treat it as low priority and focus on Organization, Article, Product and BreadcrumbList schema first.