What Is an SEO Audit? A Plain-English Guide

If you have ever been told your website "needs an SEO audit" and nodded along without being entirely sure what that meant, this guide is for you. No jargon, no upselling - just a plain explanation of what an SEO audit is, what it checks, and how to run one yourself.

Here is the short version:

An SEO audit is a health check for your website. It reviews everything that decides whether search engines - and now AI tools like ChatGPT and Google's AI Overviews - can find, understand, and recommend your pages, then tells you what is working and what to fix first.

That is the whole idea. Everything below is just detail.

What Is an SEO Audit?

Think of an SEO audit like an MOT for your website. A mechanic doesn't wait for your car to break down; they run a structured set of checks to catch the problems you can't see before they leave you stranded. An SEO audit does the same for your site: a once-over of the technical, content, and reputation signals that affect how well you show up in search.

A good audit turns a vague worry - "my site feels slow and nobody finds it" - into a specific, prioritised to-do list.

It's worth being clear about what an audit is not. It's not a single traffic-light score with no explanation. It's not a scare tactic to push you into buying something. And it's not a one-time fix - search engines, your site, and your competitors all keep changing, so an audit is a snapshot you repeat over time.

What an SEO Audit Checks

Most SEO audits look at three classic areas, and a modern audit adds a few more. Here's what each one means in plain terms.

Technical Health

This is whether search engines can actually reach, read, and index your pages in the first place - things like a valid HTTPS certificate, a working robots.txt file, an XML sitemap, and no important pages accidentally blocked or returning errors. If Google can't crawl a page, nothing else matters, because it won't rank at all. Our technical SEO guide and technical SEO checklist cover this in depth.

On-Page and Content

This is the content of each page and the signals around it: page titles, meta descriptions, heading structure, image alt text, internal links, and whether the content genuinely answers what someone searched for. Small things add up here - see our guides on meta description length, internal linking, and alt text. It's also where content quality and trust come in, which Google frames as E-E-A-T.

Off-Page Authority

This is your site's reputation - mostly the other websites that link to yours. Search engines treat a link from a relevant, trustworthy site a bit like a recommendation. You can't check this by looking at your own site; it's about how the rest of the web refers to you. For a new or small site, this is usually the slowest part to build and often the biggest thing holding rankings back.

The Modern Additions: Speed, Accessibility, and AI Readiness

A traditional audit stops at those three. A modern one goes further, because search has changed:

Speed and Core Web Vitals - Google uses page speed as a ranking factor, and slow pages lose visitors regardless of ranking. See what Core Web Vitals are and why website speed matters.
Accessibility - a site that's hard for people to use is often hard for search engines to read too, and the fixes usually overlap.
AI readiness - a growing share of searches never reach a website; the answer comes straight from an AI summary. A modern audit checks whether AI tools can find and understand your pages, not just whether Google ranks them. Our guides on whether AI crawlers can reach your site and whether ChatGPT recommends your business go deeper, and our roundup of the best AI visibility tools shows where to start.

Any one of these areas can be an audit in its own right. To go deep on a specific dimension, see our dedicated guides to a technical SEO audit, a content audit, a website accessibility audit, and a website security audit.

In plain terms: Crawling is a search engine's bot visiting your pages to see what's there. Indexing is it storing those pages so they can appear in results. On-page factors are things you control on your own site (your words, titles, and structure). Off-page factors are things other sites control (mainly links to you). A healthy site needs all of these working together.

Why Bother Running One?

Three reasons, in order of how often they actually matter:

It finds what's silently costing you traffic. Most SEO problems don't announce themselves. A page that dropped out of Google's index, a slow-loading key page, or a broken link doesn't send you an alert - it just quietly underperforms. An audit surfaces those.
It tells you what to fix first. The value isn't a list of 200 issues; it's knowing which three actually move the needle so you don't waste time on cosmetic ones.
It catches problems before they get expensive. Spotting a botched redirect, or a "noindex" tag left on after a redesign, the week it happens is far cheaper than discovering it three months and a traffic collapse later.

When Should You Run an SEO Audit?

There are four natural triggers:

When you launch a new site, so you start on solid foundations.
After a drop in traffic or rankings, to find the cause.
Before and after any big change - a redesign, a move to a new platform, or switching domains - since those are the moments things quietly break.
On a schedule the rest of the time. For most small business sites, a check every three to six months is plenty.

Can You Do an SEO Audit Yourself?

Yes. You don't need to be technical or pay an agency to get started - you have three realistic options:

Free tools. Google Search Console shows indexing and search performance, and PageSpeed Insights measures speed. They're free and accurate, but they hand you raw data and leave you to interpret it.
An automated audit tool. A free AuditCrow scan checks a page across SEO, speed, accessibility, content, trust, and AI readiness, then returns a prioritised report in plain English - no signup, and nothing to decode yourself.
A professional audit. An agency or consultant will go deeper and tailor recommendations, at a cost that in the UK typically runs from several hundred to a few thousand pounds. Worth it for larger sites or after a serious traffic loss; overkill for a five-page local business site.

Most people are best starting with a free tool to see where they stand, and only paying for help if the audit turns up something big.

How to Run a Basic SEO Audit

If you want to do a quick pass yourself, here's the short version:

Check indexing. In Google, search site:yourdomain.com and confirm your important pages show up. Google Search Console's pages report tells you more.
Check speed. Run your main pages through PageSpeed Insights and note anything in the red.
Check the basics on each key page. A unique title, a clear main heading, a meta description, and content that matches what the page is meant to rank for.
Check mobile. Open your site on a phone and make sure nothing is broken, cramped, or unreadable.
Check your links. Look for broken links, and make sure related pages link to each other.
Prioritise. Sort what you found by impact, and start at the top.

For a fuller walkthrough, see how to audit your website for SEO and our list of SEO quick wins. Once you have results, how to read a website audit report explains what to do with them.

Frequently Asked Questions

Can I do my own SEO audit? Yes. Free tools like Google Search Console and PageSpeed Insights, or an automated scanner like AuditCrow, let you run a solid basic audit without any technical background. Professionals go deeper, but you don't need one to start.

How long does an SEO audit take? A quick automated scan takes under a minute. A careful manual pass of a small site takes an hour or two. A full professional audit of a large site can take several days.

How often should I run an SEO audit? For most small business sites, every three to six months - plus any time you redesign, migrate, or notice a drop in traffic.

Do I have to pay for an SEO audit? No. You can run a genuinely useful audit with free tools. Paid audits add depth and tailored advice, which matters more for larger or more competitive sites.

Can ChatGPT do an SEO audit? It can help interpret results and explain issues in plain language, but it can't crawl your live site or measure its speed on its own. Pair it with a tool that actually scans your pages.

Whatever route you take, the point of an SEO audit is the same: to swap guesswork for a clear, prioritised picture of what's helping and what's holding your site back. If you want that picture in under a minute, run a free AuditCrow scan and see where your site stands today.