What Is a Technical SEO Audit? A Plain-English Guide

Technical SEO gets a reputation for being complicated. In reality, it's a set of checks you run on the underlying structure of your website - things Google uses to crawl, understand, and rank your pages that have nothing to do with the words on your site.

This guide explains what a technical SEO audit covers, why it matters, and what to actually look for.

What Is a Technical SEO Audit?

A technical SEO audit is a review of the behind-the-scenes factors that affect how search engines access and index your website. Think of it as a health check for the foundations, not the furniture.

When Google visits your site, it needs to:

1. Find your pages (crawling)
2. Read what's on them (rendering)
3. Store them in its index (indexing)
4. Decide where to rank them

Technical issues can break any one of these steps - and if Google can't find or read your pages, it doesn't matter how good your content is.

What a Technical SEO Audit Checks

Crawlability

Can search engines actually reach your pages? Your robots.txt file tells search engines which parts of your site they're allowed to visit. A misconfigured robots.txt is a surprisingly common way to accidentally block pages you want ranked.

Indexation

Are your pages in Google's index? Even if Google can crawl a page, it might choose not to index it - and a page that's not indexed can't appear in search results. Google Search Console's Coverage report shows you which pages are indexed and which are being excluded.

HTTPS and Security

Google uses HTTPS as a ranking signal. If your site still runs on HTTP, or has mixed content (some elements loading over HTTP while the page is served over HTTPS), you're losing trust with both visitors and search engines. A valid SSL certificate is the baseline requirement.

Page Speed and Core Web Vitals

Google's Core Web Vitals - the three speed and responsiveness metrics it uses as ranking factors - are part of any technical audit. A slow page doesn't just frustrate visitors; it ranks lower. We covered this in detail in why website speed matters.

Mobile Usability

Google uses mobile-first indexing, meaning it evaluates the mobile version of your site when deciding rankings. A site that breaks on phones, or has text too small to read, has a technical SEO problem regardless of how good the desktop version is.

Duplicate Content and Canonical Tags

If the same (or very similar) content is accessible via two different URLs, Google can get confused about which one to rank. Canonical tags tell Google which version is the "official" one and which should be ignored.

XML Sitemap

Your XML sitemap is a map of your site that you can submit to Google through Search Console, telling it exactly which pages exist and when they were last updated. A missing or outdated sitemap means Google has to discover your pages on its own - which takes longer and leaves some pages invisible.

Structured Data

Structured data (also called schema markup) is code you add to pages to tell Google exactly what the content means - a recipe, a product, a how-to guide, a business address. When implemented correctly, it can unlock rich results in search, like star ratings, FAQ dropdowns, or recipe cards.

Technical SEO Audit Checklist

Here's a quick checklist to run through:

• [ ] Site loads over HTTPS with no mixed-content warnings
• [ ] robots.txt file exists and doesn't accidentally block important pages
• [ ] XML sitemap exists and is submitted to Google Search Console
• [ ] No pages returning 404 errors unexpectedly
• [ ] Core Web Vitals scores are in the green range
• [ ] Pages display correctly on mobile
• [ ] Duplicate pages use canonical tags
• [ ] Title tags and meta descriptions exist and are unique per page
• [ ] No broken internal or external links
• [ ] Structured data implemented where relevant (business info, FAQs, etc.)

How to Run a Technical SEO Audit

You have a few options:

Manual checks — Work through the checklist above using free tools: Google Search Console for indexation and Core Web Vitals, PageSpeed Insights for speed, and Google's Mobile-Friendly Test for usability.

Automated audit tools — Tools like AuditCrow check your pages automatically and return a prioritised, plain-language report covering speed, accessibility, security, and SEO signals - without requiring any technical knowledge to read it.

A free AuditCrow scan covers the most common technical issues and flags them by severity, so you know exactly where to start. For context on what the results mean, see our guide on how to read a website audit report.

How Often to Audit

For most small business sites, once every three to six months is enough - or any time you make significant changes: a redesign, a hosting migration, switching to HTTPS. For larger or more frequently updated sites, monthly checks are worthwhile.

Technical SEO is the foundation everything else sits on. Get the foundations right first, then focus on content quality and earning links. Run a free website health check to see where your site stands today.