Technical SEO Audit Checklist for 2026 (From an Audit of Our Own Site)

23.03.2026

Technical SEO audit: computer monitor showing code.

Updated October 28, 2026.

Short answer: A technical SEO audit checks whether search engines can crawl, render, index and understand your pages, and whether those pages load well for users. Work in this order: indexing status in Google Search Console, crawlability (robots.txt, sitemaps, status codes, redirects), duplicate and canonical issues, page experience (Core Web Vitals, mobile), structured data, then internal links. Fix what blocks indexing first; cosmetic issues last.

What we found auditing our own site

In October 2026 we ran this checklist on BrandMag after a sharp drop in Google impressions. The robots.txt, canonical tags and meta robots were all fine, which ruled out a technical block. The audit did find four real problems: a plugin sending ordinary blog posts to Google’s Indexing API, which Google reserves for job postings and livestreams; a stale llms.txt file listing pages that no longer existed; redirects pointing to pages we were about to remove, which would have created redirect chains; and empty category archives. None of these caused the drop on its own, but each sent a mixed signal. The point of an audit is to remove those signals so content quality can be judged on its own.

BrandMag data center server racks with blinking indicators.

The technical SEO audit checklist

1. Indexing: is Google indexing the right pages?

Open Search Console > Pages. Compare indexed pages with the number of pages you want indexed.
Read the “Why pages aren’t indexed” reasons. “Crawled, currently not indexed” in volume usually points to quality or duplication, not a technical error.
Check Manual actions and Security issues.
Use the URL Inspection tool on your most important pages to see the rendered HTML Google sees.

2. Crawlability

robots.txt does not block important sections, CSS or JavaScript.
XML sitemap lists only indexable, canonical URLs that return 200, and is submitted in Search Console.
Status codes: crawl the site with a tool such as Screaming Frog or Sitebulb and fix internal links to 404s and 5xx errors.
Redirects: one hop only. Replace chains and loops; update internal links to point at final URLs.
Removed content: return 410 for pages gone for good with no replacement; 301 only to a genuinely equivalent page.

3. Duplicates and canonicals

One version of the site: https and either www or non-www, with the others redirecting.
Self-referencing canonical tags on indexable pages.
Parameter, tag, date and author archives that create thin duplicates are noindexed or consolidated.
Near-duplicate articles on the same topic merged into one stronger page.

4. Page experience

Core Web Vitals in Search Console: Largest Contentful Paint, Interaction to Next Paint (which replaced First Input Delay in March 2024) and Cumulative Layout Shift.
Mobile layout: readable text, tappable buttons, no horizontal scrolling. Google indexes the mobile version of your pages.
Ads and pop-ups that do not push content below the fold or cover it on mobile.

5. Rendering and JavaScript

Main content and links present in the rendered HTML, checked with URL Inspection.
Internal links use normal anchor tags with href attributes.

6. Structured data

Valid Article, Organization, BreadcrumbList and, where relevant, Product or LocalBusiness schema.
No markup describing content that is not visible on the page.
Check with Google’s Rich Results Test and the Enhancements reports.

7. Internal linking and architecture

Important pages reachable within three clicks from the homepage.
No orphan pages: every page you want indexed has internal links pointing to it.
Descriptive anchor text and logical category structure.

8. International and AI-search files

hreflang tags reciprocal and pointing to indexable URLs, if you run multiple languages.
If you publish an llms.txt file, keep it generated from live content rather than a static upload.
Do not use the Google Indexing API for ordinary pages; it is meant for job postings and livestream videos.

How to prioritize what you find

Priority	Examples
Fix now	Noindex or robots blocks on important pages, site-wide 5xx errors, wrong canonicals, manual actions
Fix this month	Redirect chains, broken internal links, poor Core Web Vitals on key templates, duplicate content
Improve over time	Internal linking depth, schema coverage, image optimization

Bottom line: Run a technical SEO audit after every major site change, not only once a year. A short technical SEO audit each quarter catches problems before they cost traffic, and a full technical SEO audit once a year keeps the basics in check.

Frequently asked questions

How often should I run a technical SEO audit?

A full audit once or twice a year, plus a monthly look at Search Console’s Pages and Core Web Vitals reports, and after any migration or redesign.

Can a technical audit fix a traffic drop?

Only if the cause is technical. If the drop matches a Google core or spam update and the site is technically clean, the problem is usually content quality.

What tools do I need?

Google Search Console, PageSpeed Insights and a crawler. See the best free SEO tools.

Sources

About the author

Erdogan Eroglu has worked in brand strategy and creative design for more than twelve years, with a focus on brand storytelling, social media advertising and building brand identities that stand apart from competitors. Erdogan on LinkedIn

Erdogan Eroglu https://www.linkedin.com/in/erogluco

For over twelve years, I have specialized in brand strategies and creative design. In my most recent experiences, I have focused on reflecting the spirit of brands and creating awareness by using my storytelling and social media advertising skills to build deep connections with the target audience. With my unique design approach and subconscious branding techniques, I have enabled brands to stand out from their competitors and showcase their unique identities.