SEO Audit
An SEO audit is a structured review of your site's ability to rank - examining technical health, on-page optimisation, content quality, and backlink profile to identify what is holding back performance and what needs to be addressed first. Running one regularly prevents small problems from compounding into significant ranking losses, and gives you a clear action list rather than a vague sense that things could be better.
According to research by SEOmator, the average website has over 4,500 crawl-detected SEO issues, and only 48% of websites pass all three Core Web Vitals on mobile. Most sites are carrying problems they are not aware of. An audit surfaces them.
The four areas of an SEO audit
Technical SEO. This covers everything that affects whether Google can crawl, render, and index your pages correctly. Start with Google Search Console's Pages report - it shows which pages are indexed, which are excluded, and the specific reason for each exclusion. Common problems at this stage include pages blocked by robots.txt, noindex tags applied unintentionally, redirect chains, and duplicate content without canonical tags. Run a full site crawl using Screaming Frog (free up to 500 URLs) or Ahrefs Site Audit to surface broken links, missing title tags and meta descriptions, pages with duplicate or missing H1s, and orphan pages with no internal links pointing to them. Check Core Web Vitals in Search Console's Core Web Vitals report and Google PageSpeed Insights - pages failing LCP, INP, or CLS thresholds are a technical priority. The full technical framework is covered in the technical SEO chapter.
On-page SEO. Review your key pages for the fundamentals: each page should have a unique, descriptive title tag under 60 characters with the primary keyword included; a meta description that accurately summarises the page and encourages clicks; a single H1 that matches the topic; and header structure that makes the content scannable. Check that primary keywords appear naturally in the opening paragraph and throughout the content without forced repetition. Look for pages with high impressions but low CTR in Search Console - these are ranking but not compelling searchers to click, which usually means the title or description needs rewriting. The on-page SEO chapter covers each element in depth.
Content. Use Google Analytics and Search Console together to identify underperforming content. Pages with high organic traffic but low engagement rate or no conversions are ranking for queries they do not fully satisfy. Pages that have received no organic traffic in twelve months are candidates for updating, consolidating, or removing. Check for keyword cannibalisation - multiple pages targeting the same keyword and competing with each other. Use Ahrefs' Content Gap tool or Semrush's Keyword Gap to find topics your competitors rank for that you do not. The content pruning page covers this process in detail.
Backlinks. Run your domain through Ahrefs Site Explorer or Semrush's Backlink Analytics. Check how many referring domains you have, how that number is trending over time, and whether the links are from relevant, credible sources. According to Backlinko's analysis of 11.8 million search results, the top result in Google has 3.8x more backlinks than pages in positions 2-10 - which makes your backlink profile directly relevant to whether your best pages can reach their ranking potential. Look at which pages are earning the most links and whether those are the pages that matter most for your business goals. Identify any obvious link gaps relative to the pages that outrank you for your target keywords.
How to prioritise what you find
Every audit produces a list of issues. Without prioritisation, the list sits untouched or the lowest-effort items get fixed first regardless of their impact. A useful framework is to sort findings by two variables: how much the issue is likely to affect rankings, and how much effort it takes to fix.
The order to work through issues, as BizChecklistTools recommends: start with crawl errors and Core Web Vitals, then on-page and content issues, then backlink gaps. The reasoning is that a clean technical foundation accelerates everything else - content and backlinks cannot perform at their potential if Google cannot crawl and index the pages they are on. A well-optimised page on a technically broken site ranks worse than a moderately optimised page on a clean one.
Quick wins - pages with high impressions and low CTR that need a title rewrite, pages with thin content that can be quickly expanded, broken internal links that take minutes to fix - are worth doing alongside the higher-effort work. They add up.
How often to run an audit
For most sites, a thorough audit every three to six months is appropriate. A monthly technical crawl using Screaming Frog or Ahrefs catches new issues introduced by content updates, site changes, or CMS migrations before they cause visible ranking damage. Run a full audit immediately after any significant site migration, after an unexplained traffic drop, or following a confirmed Google core update that affected your rankings.
An audit is most useful when it produces a prioritised action plan rather than a report. The point is not to document every issue on your site - it is to identify the changes that will most improve your rankings, and do them.
With this page, the Measuring SEO chapter is complete - and with it, the core curriculum of this guide. Every chapter from how search engines work through to measuring the results of your work has now been covered. The Learn SEO hub links back to every chapter and sub-page for easy reference.