Technical SEO: Audit and Checklist for 2026

What does a technical SEO audit cover?

The review answers three key questions: can the search engine reach the pages, can it choose the correct version to index, and can it understand their content? You then check whether the site works properly for people on mobile devices and whether technical limitations are getting in the way of enquiries and sales.

How do you check crawling and indexing?

robots.txt

Check that important folders, CSS, JavaScript or images are not blocked. Administrative panels, internal search and technical directories are usually restricted. A rule such as Disallow: / left over from a test environment is especially dangerous, as is an automatic plugin setting that blocks the entire site.

Test real URLs with URL Inspection in Google Search Console. Do not check only the homepage. Choose a homepage, service page, category, product and page with a form. This will show whether Googlebot has access, which canonical version was selected and why a given URL is excluded.

XML sitemap

The sitemap should contain the indexable canonical URLs you want to grow. Do not add 404 pages, redirects, noindex URLs or filters with no SEO value. Submit the file in Search Console and compare the submitted URLs with those that are actually indexed.

Canonical, Parameters and Duplication

Filters, sorting, UTM parameters and different versions of the same product can create multiple URLs with almost identical content. A canonical tag indicates the preferred version, but it does not replace a clear structure, proper internal links and parameter control. It should point to an accessible, indexable and genuinely equivalent URL.

Internal links

Important services and categories should be accessible from the main navigation or from meaningfully related pages. Look for orphan pages, pages with no internal links. Link to them where the user would naturally continue, rather than relying solely on buttons that appear after JavaScript runs.

What should you check about speed and Core Web Vitals?

Core Web Vitals do not improve with the press of a button. A slow site may be the result of hosting, a large image, blocking JavaScript, an external chat widget, advertising pixels or a heavy database query. Compare lab tests with real-world data and check different templates: product page, article, cart and landing page.

HTTPS is the mandatory foundation. Check the certificate, the HTTP-to-HTTPS redirect and mixed content, resources that are still loaded over HTTP. After a migration, update internal links, canonical URLs, sitemap and tracking settings.

How do you check the mobile version and key functionality?

Google uses the mobile version for crawling and indexing. Headings, main text, internal links, structured data and key functionality must also be available on a phone. Content in a tab or accordion is not automatically a problem, but the mobile version should not be significantly poorer than the desktop version.

Carry out a real-world test of forms, dropdown menus, search and filters. For an online store, include the cart, cash on delivery, card payment and waybill creation if these functions are part of the process. SEO traffic has no business value if the customer cannot submit an enquiry or complete an order. With online store development, these checks should be part of acceptance, not a task after publication.

URLs should be short and clear, with one consistent structure and hyphens between words. Do not change a working URL without a 301 redirect plan. During a redesign, create a table of the old and new URLs before uploading the site. This allows redirects to be tested before the change reaches users.

What happens when a site uses JavaScript?

With React, Vue or another JavaScript technology, do not assume that what a person sees is the same as what Googlebot receives. Check the HTML response before scripts run and the rendered version. The main heading, text, products, links and metadata should not depend on a failed API request or a script that loads too late.

Filters, pagination, infinite scrolling and internal search require particular attention. If important products are accessible only after clicking a button, Google may not discover them in the same way as the user. Make categories indexable and provide clear links to the pages that drive organic search.

When does schema help and when does it hurt?

Structured data helps the search engine understand whether a page is a service, product, article, organization, event or frequently asked question. It does not guarantee a rich result and does not replace useful content, a clear structure and a high-quality page.

Mark up only information that is actually visible. Do not add ratings, prices, availability or questions that the user cannot find on the page. Validate the syntax and compare the schema with the actual business content. Incorrect markup can create more problems than benefits.

How should you prioritize a technical SEO audit?

1. 01
   Gather access details and baseline data

   You need Google Search Console, analytics, access to the CMS and hosting, a list of important services or products, and information about recent changes. Without this data, part of the audit inevitably becomes guesswork.

2. 02
   Crawl the site and export the data

   Check URLs, status codes, headings, canonical tags, robots directives, internal links, images and duplicate templates. Compare the pages found with the sitemap and with the URLs that actually generate enquiries.

3. 03
   Verify critical URLs in Search Console

   Test representative pages with URL Inspection. Check indexing, the selected canonical version, mobile rendering and the reasons for exclusion.

4. 04
   Create a developer backlog

   Each task should include a URL or pattern, a reason, a priority, the expected result and a way to verify it. “All pages with parameter X should point to category Y” is more useful than “optimise the canonical”.

5. 05
   Check after the change

   Run the crawl again, test the actual forms and orders, and monitor Search Console. After a redesign or migration, the checks do not end on the day of publication.

What does a useful audit result look like?

A good result is a short list of risks and clear actions. A blocked important URL, an incorrect migration or a form that fails to submit are critical issues. Lower-priority issues include improvements that do not affect indexing, navigation or conversions.

For a company website, the structure should lead to a genuine enquiry. For an online store, it should keep categories, products and the checkout process accessible. With a complex system, it is cheaper to build SEO requirements in from the start during website development, rather than fix them after publication. When changing an existing website, check the old URLs and redirects during the planning stage, as described in website redesign.

Technical SEO is not separate from the business. A broken service page means a missed enquiry, while a slow checkout means an abandoned order. So prioritise tasks by their risk to visibility and revenue, not by which error looks easiest to fix. With SEO optimisation, a technical audit can provide the foundation for a broader plan covering structure, content and measurement.