How to Do an SEO Audit: A Step-by-Step Guide

Polishing the content on a page Google can’t crawl yet wastes the effort completely, and it’s the single most common order-of-operations mistake in how to do an SEO audit properly. A genuine SEO audit guide marketers can trust won’t reshuffle that order to match whichever section feels most urgent that week: technical health first, then on-page factors, content, backlinks and competitors.

What Is an SEO Audit and Why Do You Need One?

A page’s Google ranking can slip from position four to position nine, and the first sign of it is often a slightly worse sales report three months later. Knowing how to do an SEO audit and running one on a schedule catches that drop early, before it turns into a mystery someone has to reverse-engineer from old rankings data.

“Is the SEO good” is too vague a question for an audit to answer against anything concrete. A website SEO audit breaks that question into dozens of separate checks instead, each one either passing cleanly or producing a specific, actionable finding. We’d rather hand a client a dozen boring pass marks and three clear fixes than a vague “it’s looking okay overall” after a day of digging. Every one of those checks gets covered below, in the order they need doing.

Step 1: Technical SEO Audit

“Discovered, currently not indexed.” That status in Google Search Console’s coverage report means Google already knows the URL exists, usually from a sitemap or another page linking to it, but hasn’t got around to crawling it yet. On most sites that comes down to weak internal linking or a page Google suspects is thin or duplicate content; on a much larger site, genuine crawl budget limits can be the real cause instead.

We run that exact report before touching anything else on a new audit. How to do an SEO audit properly always begins there.

Fixing the internal linking side means adding links from pages Google already has indexed, then running the URL back through Search Console’s URL Inspection tool to request a crawl directly. A thin or duplicate-sounding page usually needs expanding or merging before that request stands any real chance, since Google won’t prioritise crawling content it already suspects isn’t worth indexing.

Largest Contentful Paint and Cumulative Layout Shift scores matter here too. PageSpeed Insights and Search Console’s own Core Web Vitals report both draw on the same real-visitor field data, but PageSpeed Insights reports on one specific URL while Search Console groups similar URLs together and scores the group as a whole, so a single page can look fine on its own and still sit inside a “poor” group. We use Search Console’s grouped view to judge overall site status and PageSpeed Insights to debug one specific page.

Ahrefs’ Site Audit and Semrush’s Site Audit both automate most of this layer, crawling a full domain in one pass and flagging broken canonicals, HTTPS issues and indexability problems that would otherwise take hours to find by hand. Worth the cost on anything beyond a handful of pages, and a genuine time-saver for how to do an SEO audit on a large site specifically.

Step 2: On-Page SEO Audit

Most Shopify themes append the store name to every title tag through the theme’s own code, something editing the product’s SEO title field does nothing to fix. A site with 2,000 products ends up with 2,000 near-identical title tags, all fighting for the same handful of keywords, and an export checked for duplicates catches it in minutes.

We treat this as a quick win whenever we find it on a client site. A bulk rewrite through the platform’s own export tool doesn’t take long, and it’s exactly the kind of platform default a website SEO audit exists to catch before it quietly caps how any of those pages can rank.

Two separate problems hide inside “heading structure.” Multiple H1 tags confuse which headline matters most on a page, and a jump straight from H2 to H4 skips a level entirely. Both read fine to a human skimming the page and badly to Google trying to parse its structure.

Every page on the site needs at least one internal link pointing to it from somewhere else, full stop. Alt text gets checked last in this step and skipped most often. That single oversight costs a site both accessibility compliance and a ranking signal for image search, in one move.

A meta description won’t move a ranking on its own, but Google rewrites it anyway on plenty of search results, swapping in its own snippet from the page content instead. The real question for this part of a website SEO audit isn’t whether a meta description exists, it’s whether it would still earn a click if Google used it as written. Missing or duplicated meta descriptions across near-identical product or category pages is the most common finding we come across here.

Structured data causes a different kind of problem, because broken JSON-LD often looks fine at a glance and only fails on a required field, like Product schema missing a price or an availability status. That single missing field quietly disqualifies the page from rich results, with no obvious error anywhere in the page’s visible content. We run every templated page type through Google’s Rich Results Test before signing off a technical audit, not just the homepage, since one broken template can carry the same error across thousands of pages.

Step 3: Content Audit

Position three for “how does work” looks like a win, right up until Google Search Console’s query report, filtered down to that one URL, tells a different story. We always check that query report before celebrating a ranking like this with a client. Plenty of clicks, a conversion rate that barely registers, because everyone landing on it wanted an explanation, not a purchase decision.

Turning that page into a genuine explainer, with the buy button moved down rather than deleted, is usually the single highest-impact fix anywhere in the whole SEO audit checklist.

Cross-referencing every URL on the site against organic traffic and rankings surfaces the thin pages too, ones running a few hundred words with no real reason to exist on their own. We’d always consolidate here rather than delete outright, since the merged page tends to keep whatever backlinks and ranking history the originals had already picked up.

Splitting a single keyword’s ranking signal across two competing pages leaves neither one performing as well as a consolidated page would. Mapping every target keyword against its one owning page, done once across the whole SEO audit process, surfaces this directly.

Step 4: Backlink Profile Audit

Backlinks arriving suddenly from unrelated foreign-language domains rarely mean a site got popular abroad overnight. More often it’s a negative SEO attack, or a previous agency’s bad practices finally catching up months after the contract ended. It’s the first thing we check whenever a client’s rankings drop without an obvious on-site cause, right there in the backlink profile’s own timeline view.

Referring domain count matters less on its own than its trend over the past year, growing, flat, or quietly declining. We watch that trend line in every monthly client report we send. A falling trend almost always traces back to content or outreach work that stopped without anyone deciding to stop it. “Best SEO agency London,” repeated as the anchor text across dozens of links, reads as manufactured to Google no matter how the links themselves were acquired. A natural anchor profile leans on branded and generic phrasing instead, with exact-match commercial anchors sitting at a small fraction of the total link count.

Step 5: Competitor Gap Analysis

Keywords a business hadn’t even thought to target usually surface fastest through a competitor’s own rankings, not through fresh keyword research. We run this exercise early in every audit: pulling the top three organic competitors for the business’s main terms, then running a content gap report between their site and its own. The content need it surfaces is already proven by someone else’s existing traffic.

The same logic works on links instead of keywords: which domains already link to three competitors but not to the business being audited? That domain has a demonstrated habit of linking to businesses in this exact space. It’s a realistic outreach target, found straight out of the audit.

SERP features tell a third story the ranking data alone won’t. A competitor holding the featured snippet or the top spot in People Also Ask for a target query usually means their page answers the question in a format Google can lift directly, a short definition, a numbered list, a table, whichever the competitor’s page happens to use. We check which SERP features show up for the business’s main terms and who currently holds each one, then build the fix straight into the content brief.

Prioritising Fixes by Impact

Sixty items on an SEO audit checklist, every one treated as equally urgent, is how most of them end up never actioned at all. We score every finding against two numbers before it goes anywhere near a client report: how much traffic or revenue the affected page already generates, and how much effort the actual fix takes.

We’d fix the homepage’s broken canonical tag first, every time. It’s cheap to fix and sits on the site’s single most important page, clearing both bars easily. A missing alt tag on a 2019 blog post getting three visits a month barely registers on either one.

How Often Should You Audit Your SEO?

We tell stable, mature clients once or twice a year is plenty, then adjust that cadence based on how fast the site is changing day to day. A site mid-redesign, mid-migration, or publishing aggressively needs that same SEO audit process run lighter, monthly.

These checks belong inside ongoing work, not sold separately as a one-off audit and never repeated. An SEO agency business trusts should be running them as a standing part of the relationship.

Technical SEO and the keyword research process both feed directly into what an audit finds. We check both on every engagement, because an audit covering only technical health just confirms the site works, never whether it’s aiming at the right terms in the first place.