Technical SEO audit checklist

A technical SEO checklist answers one question: can search engines reach, read and index every page that matters. Work through the sections below in order. The early sections cover faults that stop pages from appearing at all. The later ones cover faults that hold good pages back.

Google sets only three technical requirements for a page to be eligible for Search: Googlebot is not blocked, the page works and returns a success status, and the page has indexable content. Meeting them does not guarantee indexing. Everything in this checklist either protects those three or builds on them.

Before you start

• Verify the site in Google Search Console. Most of the checks below use its reports.
• List the pages that should appear in search results. An audit compares what is indexed with what should be.
• Crawl the site with a crawling tool to get a full list of URLs, status codes and tags.

1. Crawling

• Open the robots.txt file and confirm it does not block pages, scripts or stylesheets that Google needs. Google warns that blocking resource files can make pages harder to analyse.
• Remember what robots.txt is for. Google describes it as a way to manage crawler traffic, not a way to keep a page out of search. A blocked page can still appear in results without a description.
• Check that the hosting firewall or content delivery network is not blocking search engine crawlers.
• Confirm that important pages are not behind a login.
• Check that every important page can be reached by following links from the home page.

2. Indexing

• Compare the indexed pages in Search Console with the list of pages that should be indexed.
• Look for stray noindex tags, for example ones left over from a staging site.
• To keep a page out of Google, use noindex or password protection. Do not rely on robots.txt.
• Confirm that live pages return a 200 status and that removed pages return a proper error or a redirect.
• Check that the main content is in text form in the page, not only in images or loaded after a user action.

3. Sitemaps

• Check whether the site needs one. Google says a sitemap helps most on large sites, new sites with few external links and sites with many images or videos. A small site of about 500 pages or fewer with sound internal linking may not need one.
• If there is a sitemap, include only the canonical, indexable HTTPS URLs and submit it in Search Console.
• A sitemap does not guarantee that the listed pages will be crawled or indexed.

4. Duplicate URLs and canonicals

The same page can be reachable at several addresses: with and without www, with tracking parameters, or through category and tag archives. Google's guidance on canonical URLs ranks the signals from strongest to weakest: redirects, the rel=canonical tag, then sitemap inclusion.

• Redirect duplicate versions of the domain to one preferred version.
• Add a self-referencing canonical tag to each page, using absolute URLs.
• Make sure the canonical tag, the sitemap and the internal links all point to the same URL.
• Do not use robots.txt or noindex to choose a canonical.
• Check that two pages are not competing for the same topic. Stryx builds one topic per page for this reason.

5. HTTPS

• Confirm the certificate is valid and covers every host name the site uses.
• Redirect HTTP to HTTPS on every URL.
• Remove HTTP links from the sitemap and from internal links.
• Check for pages that load insecure scripts or files.

6. Mobile content

Google uses the mobile version of a site for indexing and ranking.

• Confirm the mobile layout shows the same main content, headings, titles and meta descriptions as the desktop layout.
• Check that structured data is present on both.
• Make sure primary content does not depend on a tap or swipe to load.
• Check that images have the same alt text on both.

7. Speed and Core Web Vitals

Google's Core Web Vitals thresholds for a good result are:

• Largest Contentful Paint within 2.5 seconds
• Interaction to Next Paint under 200 milliseconds
• Cumulative Layout Shift below 0.1

Check the Core Web Vitals report in Search Console, then test the slowest page templates. Look at image sizes, the number of scripts and the hosting. See speed optimisation for how Stryx approaches fixes.

8. Structured data

• Use JSON-LD, the format Google recommends.
• Mark up only what is visible on the page, and keep it accurate.
• Test templates with Google's Rich Results Test and watch Search Console for errors.
• Valid markup makes a page eligible for a feature. It does not guarantee the feature.

The guide to schema markup for service businesses has working examples.

9. Redirects and broken links

• Find internal links that point to missing pages and fix the link, not just the destination.
• Use permanent server-side redirects for moved pages.
• Redirect each old URL straight to its final address. Google can follow up to 10 hops, and advises keeping chains short.
• Do not redirect many old pages to the home page. Google may treat that as a soft 404.
• After a rebuild, keep redirects for at least a year. Stryx redirects old URLs whenever a site is replaced.

10. Access for AI search

• Google states there are no extra technical requirements to appear in AI Overviews or AI Mode. A page must be indexed and eligible to show a snippet.
• Check the Search generative AI control in Search Console. It is set to include by default. If someone has set it to exclude, the site will not appear in those features.
• To be eligible for ChatGPT search, OpenAI says a site must allow its OAI-SearchBot crawler. Check robots.txt and any firewall rules.
• No special file is needed. Google says its Search does not use llms.txt.

After the audit

Sort the findings by effect. Anything that stops pages being crawled or indexed comes first. Duplicates, redirects and mobile content come next. Speed and structured data follow. Then re-check after the fixes, and again whenever plugins, themes or hosting change.

Stryx carries out this work as technical SEO and as part of every SEO audit. To have a site checked, get in touch.