An SEO audit is a full check-up of your website's health across technical setup, on-page content, and off-page authority. It tells you exactly what's stopping your pages from ranking, and what to fix first.

Whether you run an ecommerce store, a SaaS site, or a local business page, an SEO audit is the starting point before any real optimisation work begins. This guide walks through the process step by step, so you can run one yourself or brief your team clearly.

What Is an SEO Audit?

An SEO audit is a systematic review of a website's performance across three areas: technical health, on-page optimisation, and backlink profile. The goal is to identify issues that block search engines from crawling, indexing, or ranking a site, and to find opportunities to improve visibility.

A good audit doesn't just list problems, it ranks them by impact, so you know what needs fixing straight away and what can wait.

Why is an SEO Audit Important?

Search engines change their algorithms constantly, and websites accumulate issues over time: broken links, outdated content, slow-loading pages, and duplicate URLs. An audit catches these before they cost you rankings and traffic.

Regular audits also help you:

• Spot technical errors before they compound

• Understand which pages are underperforming and why

• Find content and keyword gaps competitors are exploiting

• Confirm your site meets current Core Web Vitals and mobile usability standards

• Build a prioritised action plan instead of guessing what to fix

How to Perform an SEO Audit: Step-by-Step

Follow these steps in order, starting with a full site crawl and ending with a prioritised action plan. Each one builds on the last, so skipping ahead usually means backtracking later.

Step 1: Crawl Your Website

Start with a full site crawl using a tool like Screaming Frog, Sitebulb, or Ahrefs Site Audit. This gives you a complete map of your URLs, status codes, redirects, and metadata in one place.

Step 2: Check Indexing and Crawlability

Confirm search engines can actually find and index your pages.

• Review your XML sitemap to make sure it's submitted, up to date, and free of broken or non-canonical URLs

• Check your robots.txt file for accidental disallow rules

• Use Google Search Console's Coverage report to find pages excluded from the index

• Look for orphan pages with no internal links pointing to them

Step 3: Run a Technical SEO Audit

A technical SEO audit looks at the infrastructure behind your site. Key checks include:

• Site speed and page load times

• Mobile responsiveness and usability

• HTTPS and security setup

• Broken links and 404 errors

• Duplicate content and canonical tags

• URL structure and redirect chains

Step 4: Evaluate Core Web Vitals

Core Web Vitals are Google's measurable standards for user experience, and they directly affect rankings. Check these three metrics in Google Search Console or PageSpeed Insights:

• Largest Contentful Paint (LCP): should load within 2.5 seconds

• Interaction to Next Paint (INP): should respond within 200 milliseconds

• Cumulative Layout Shift (CLS): should stay below 0.1

Pages failing these thresholds need image compression, code minification, or server response improvements.

Step 5: Audit On-Page Elements

Go through your top pages and check:

• Title tags and meta descriptions are unique and keyword-relevant

• H1 tags are present and match search intent

• Header structure (H2s, H3s) is logical and not skipped

• Images have descriptive alt text

• Internal links connect related pages

• Content matches the search intent for its target keyword

Step 6: Check for Keyword Cannibalisation

Search your site for multiple pages targeting the same keyword. This confuses search engines about which page to rank and splits your authority. Consolidate or differentiate these pages.

Step 7: Review Content Quality and Gaps

Identify thin, outdated, or duplicate content. Compare your content depth against top-ranking competitors for your target keywords, and note any subtopics they cover that you don't.

Step 8: Audit Backlinks

Use a tool like Ahrefs, SEMrush, or Moz to review your backlink profile:

• Check for toxic or spammy backlinks that could trigger a penalty

• Identify lost backlinks that need reclaiming

• Compare your referring domains against competitors

Step 9: Add Structured Data

Implement schema markup (Article, FAQPage, Product, or LocalBusiness, depending on the page) so search engines and AI systems can parse and display your content more accurately in search results and AI-generated answers.

Step 10: Compile and Prioritise Findings

Bring everything into a single report, ranked by impact and effort. Fix critical crawl and indexing errors first, then move to on-page and content issues, then link-building opportunities.

SEO Audit Checklist

Here's a condensed checklist you can run through quickly:

1. Site crawled and indexed correctly

2. XML sitemap submitted and error-free

3. Robots.txt reviewed for blocking issues

4. Core Web Vitals within recommended thresholds

5. Mobile usability confirmed

6. Title tags and meta descriptions optimised

7. Header tags structured logically

8. Internal linking in place across key pages

9. No keyword cannibalisation across pages

10. Backlink profile reviewed for toxic links

11. Schema markup implemented on key page types

12. Content gaps identified against competitors

SEO Audit Tools Compared