How to Do an SEO Audit: A Step-by-Step Checklist
What is an SEO audit?
An SEO audit is a structured review of a website that finds the issues stopping it from being crawled, indexed, understood and ranked, then sorts the fixes by impact. A complete audit checks technical health, on-page elements, content quality, internal links, backlinks and page experience signals such as Core Web Vitals. The result should be a prioritised action plan, not just a list of errors.
When to run an SEO audit
- Before and after a redesign, platform change or domain migration.
- After an unexplained drop in organic traffic.
- When you take over a new website or client.
- On a regular schedule, such as every quarter for active sites, with lighter monthly checks.
Gather access before starting: Google Search Console, GA4, the CMS, the hosting or server logs if available, and a site crawler. Record baseline numbers for clicks, impressions, indexed pages and key conversions so you can measure the effect of fixes.
Step 1: crawling and indexing
If search engines cannot reach or index a page, nothing else matters. This part overlaps heavily with technical SEO.
- Check robots.txt for rules that block important sections, scripts or stylesheets.
- Confirm the XML sitemap lists only indexable, canonical URLs that return a 200 status.
- Review the Page indexing report in Search Console for excluded pages and their reasons.
- Look for stray
noindextags on pages that should rank. - Find broken pages (4xx), server errors (5xx), redirect chains and redirect loops.
- Check canonical tags and duplicate URLs created by filters, tracking parameters or HTTP and HTTPS versions.
# A robots.txt mistake found in many audits
User-agent: *
Disallow: /
# What was intended: block only internal search results
User-agent: *
Disallow: /search/
Sitemap: https://www.example.com/sitemap.xmlStep 2: page experience and mobile
Google indexes the mobile version of pages, so audit the site on a phone first. Then review Core Web Vitals in Search Console, which uses real user data.
| Metric | Measures | Good threshold |
|---|---|---|
| Largest Contentful Paint (LCP) | Loading of the main content | 2.5 seconds or less |
| Interaction to Next Paint (INP) | Responsiveness to taps, clicks and key presses | 200 milliseconds or less |
| Cumulative Layout Shift (CLS) | Visual stability while loading | 0.1 or less |
INP replaced First Input Delay as a Core Web Vital in March 2024. Also check HTTPS, intrusive pop-ups and whether text is readable without zooming.
Step 3: on-page elements and content
- Missing, duplicate or truncated title tags and meta descriptions.
- Pages without a clear H1 or with headings that do not reflect the content.
- Thin or near-duplicate pages that add little value.
- Several pages competing for the same query (keyword cannibalisation).
- Outdated content with old prices, dates or instructions.
- Pages whose format does not match what searchers expect.
Use the on-page SEO guide for fixing page elements and the content SEO guide for deciding whether to update, merge or remove weak pages.
Step 4: links, rendering and structured data
- Find orphan pages that no internal links point to, and broken internal links.
- Check that important pages sit within a few clicks of the home page.
- Review the backlink profile for lost links and obvious spam patterns, as described in the off-page guide.
- Compare initial and rendered HTML on JavaScript-heavy templates.
- Check structured data reports in Search Console for errors and invalid items.
Prioritising what to fix
An audit can surface hundreds of issues. Rank them by likely impact and effort, and fix blockers first.
| Issue | Impact | Effort | Priority |
|---|---|---|---|
| Key category pages set to noindex | High | Low | Fix immediately |
| Product template missing canonical tags | High | Medium | Fix this sprint |
| Slow LCP on mobile blog pages | Medium | Medium | Plan next |
| Some meta descriptions too long | Low | Low | Batch with routine updates |
Fixing a blocker on a few important pages usually matters more than fixing a minor warning on every page.
Writing up and following through
A useful audit report is short at the top and detailed underneath. Structure it so each reader finds what they need:
- Summary: the three to five issues that most affect search visibility, in plain language.
- Evidence: screenshots, example URLs and the Search Console report or crawl export behind each finding.
- Recommendations: what to change, on which template or section, and who owns the task.
- Measurement plan: which metrics to watch after each fix and when to check them.
Re-crawl the site after fixes go live and compare the results with your baseline. Indexing and ranking changes take time, so review clicks and impressions over several weeks rather than days. Running full audits on real sites is a central project in our online fundamentals-to-advanced SEO course.
Common mistakes
- Delivering a long export of tool warnings without explaining which issues matter.
- Treating every tool warning as an error, even when it has no effect on search.
- Auditing only the desktop version when Google indexes the mobile version.
- Skipping a baseline, which makes it impossible to prove that fixes worked.
- Fixing issues page by page instead of correcting the template that causes them.
Frequently asked questions
How long does an SEO audit take?
A small business site can be reviewed in a day or two. Large e-commerce or news sites with many templates and thousands of URLs can take several weeks.
Can I do an SEO audit with free tools?
Yes. Search Console, PageSpeed Insights, Lighthouse and a free crawler tier cover most technical checks. Paid tools add backlink and competitor data. See the tools overview.
Should I fix every warning a tool reports?
No. Tools flag anything that might be a problem, including issues with no real effect on search. Check whether each warning affects important pages before adding it to the plan.
What is the difference between an audit and ongoing SEO?
An audit is a snapshot that finds problems and sets priorities. Ongoing SEO is the continuous work of fixing those issues, creating content and earning links.