How to Do an SEO Audit (Step by Step)

An SEO audit is a structured review of a site's technical health, on-page content and off-page authority to find what is holding back its rankings and decide what to fix first. The most useful audits are not a giant undifferentiated list of problems — they are a prioritised action plan, ranking issues by impact and effort so you fix the things that matter soonest. The reliable way to run one is in four phases: technical, on-page, off-page, and reporting/prioritisation, with Google Search Console as the foundation because it shows how Google actually sees your site. This guide walks through each phase step by step, the tools to use, and how to turn findings into a plan.

It draws together many threads, so it pairs naturally with what is technical SEO and how to audit it for the technical detail.

Before you start: gather your tools and baseline

A good audit begins with access and a baseline. Make sure you have Google Search Console verified for the site (it is free and indispensable), an SEO crawler such as Screaming Frog to crawl the site like a search engine, PageSpeed Insights for performance, and analytics for traffic context. For large sites, arrange access to server logs for real crawl analysis. Then capture a baseline: current organic traffic, indexed page count, Core Web Vitals status, and rankings for key terms, so you can measure the impact of the fixes you make.

Here is the audit at a glance — each area, the core checks, and the primary tool — before we work through them in order.

Area	Core checks	Primary tool
Technical: crawl & index	Crawlability, indexing status, robots, sitemap, canonicals	Search Console (Pages), crawler
Technical: speed	Core Web Vitals, page weight, render-blocking	PageSpeed Insights, Search Console
Technical: mobile & HTTPS	Mobile usability, HTTPS everywhere, mixed content	Search Console, browser dev tools
On-page: elements	Titles, meta descriptions, headings, structured data	Crawler, manual review
On-page: content & intent	Quality, depth, search-intent match, duplication	Manual review, Search Console (Performance)
On-page: internal links	Internal link structure, orphan pages, anchor text	Crawler
Off-page	Backlink profile, reputation, brand mentions	Backlink tools, manual review
Reporting	Prioritise by impact vs effort; action plan	Spreadsheet / audit report

Phase 1: the technical audit

The technical phase asks the foundational question: can search engines crawl, render and index the site properly, and is it fast and accessible? If the answer is no, nothing else matters, so this comes first.

Crawl the site

Run an SEO crawler (Screaming Frog or similar) across the site to simulate how a search engine sees it. The crawl surfaces broken links (404s), redirects and redirect chains, duplicate or missing titles and meta descriptions, duplicate content, broken images, orphan pages and server errors at scale. This single step typically uncovers a large share of an audit's findings, and it gives you a map of the site's URL inventory to work from.

Check indexing in Search Console

Open the Pages (Indexing) report in Google Search Console to see which URLs Google has indexed and which it has not, grouped by reason — 404s, soft 404s, server errors, blocked by robots.txt, excluded by noindex, "crawled - currently not indexed," and more. This is the authoritative view of how Google treats your site, and diagnosing it is covered in depth in how to fix crawl errors in Google Search Console. Confirm that important pages are indexed and that nothing valuable is accidentally excluded.

Review robots, sitemap and canonicals

Check the three files and signals that govern crawling and indexing. Confirm your robots.txt is not accidentally blocking important pages — see how to write a robots.txt file. Confirm your XML sitemap lists your canonical, indexable URLs and is free of redirects and errors — see how to create an XML sitemap and submit it. And check canonical tags are correct and consistent, not pointing pages at the homepage or contradicting your sitemap — see what are canonical tags and how to use them.

Assess speed and Core Web Vitals

Performance is both a ranking factor and a user-experience issue. Use the Core Web Vitals report in Search Console for a site-wide, field-data view, and PageSpeed Insights for individual pages. Look at Largest Contentful Paint, Interaction to Next Paint and Cumulative Layout Shift, and identify the templates (not just single pages) that are slow, since fixing a slow template improves every page that uses it. Speed also feeds crawl budget on large sites.

Check mobile-friendliness and HTTPS

Confirm the site works well on mobile, since Google indexes mobile-first — check for unusable layouts, tiny tap targets and content that differs between mobile and desktop. Confirm the whole site is served over HTTPS with no mixed-content warnings (HTTP resources on HTTPS pages), and that HTTP URLs 301-redirect to HTTPS, as covered in what is a 301 redirect and when to use it.

Phase 2: the on-page audit

With the technical foundation checked, the on-page phase asks: does each important page target the right intent with strong content and clean on-page elements?

Audit titles and meta descriptions

Use the crawler's output to find missing, duplicate, too-long or too-short title tags and meta descriptions. Every important page should have a unique, descriptive title that reflects its target query, and a compelling meta description that earns the click. Duplicate titles across many pages are a common, easily-fixed finding that also hints at thin or duplicative content underneath.

Review headings and structure

Check that pages use a logical heading hierarchy — a single clear H1 describing the page, with H2s and H3s structuring the content beneath it. Good heading structure helps both users and search engines understand a page, and question-style headings help with featured snippets and AI answers. Flag pages with no H1, multiple competing H1s, or headings used purely for styling.

Assess content quality and search-intent match

This is the editorial heart of the audit, and it is largely manual. For your important pages and target queries, ask: does the content match the search intent behind the query (informational, commercial, transactional)? Is it thorough and genuinely useful, or thin and surface-level? Is it accurate and current? Is there duplication or cannibalisation, where several pages compete for the same query and should be consolidated? Cross-reference the Performance report in Search Console to see which pages and queries already earn impressions and clicks, and where you rank on page two — those near-misses are often the highest-value content opportunities.

Check internal linking

Use the crawler to review internal link structure. Important pages should be well-linked and reachable within a few clicks of the homepage; orphan pages (linked from nowhere) should be linked in or removed. Check that anchor text is descriptive rather than "click here," and that your most important pages receive the most internal links, since internal linking is how you signal page importance and distribute authority around the site.

Review structured data

Check for schema markup where it adds value — Article, FAQPage, Product, Organization and so on — and validate it. Structured data helps search engines understand and richly display your content, and it overlaps with AI-search readiness. If you are also thinking about generative engines, how to check if your site is ready for AI search extends the on-page review toward GEO.

Phase 3: the off-page audit

The off-page phase asks: does the site have the authority and reputation to compete? Most ranking strength beyond the page itself comes from how the rest of the web regards you.

Review your backlink profile with a backlink tool: how many referring domains link to you, their quality and relevance, and your anchor-text distribution. Look for toxic or spammy links that may need disavowing, and identify link gaps where competitors earn links you do not. Beyond links, assess brand reputation and mentions — reviews, citations and unlinked brand mentions all contribute to how authoritative and trustworthy you appear, which ties into E-E-A-T. Off-page is the slowest area to change, so the audit's job here is mostly to understand where you stand and identify a realistic link-and-reputation strategy rather than promising quick fixes.

Phase 4: reporting and prioritisation

This phase is what separates a useful audit from a useless one. A crawl and a stack of reports produce dozens or hundreds of findings; dumping them all on a developer as an undifferentiated list guarantees nothing gets done. The value you add is prioritisation.

Score each finding on two axes: impact (how much will fixing it help?) and effort (how hard is it to fix?). That yields a simple priority order:

• High impact, low effort — do these first. Indexing blockers (accidental noindex, robots.txt blocks), broken important pages, a slow shared template, missing titles on key pages, redirect chains. These are the quick wins that recover visibility fast.
• High impact, high effort — plan these next. Site migrations, a content-quality overhaul, fixing a deep architectural problem, a major performance rebuild.
• Low impact, low effort — batch these as housekeeping. Minor meta-description tweaks, small structured-data additions.
• Low impact, high effort — usually defer or drop.

Present the findings as an action plan, not a problem list: each item with its priority, the specific fix, the owner, and the expected benefit. Tie it back to the baseline you captured, so you can measure improvement after the fixes ship. This is also where you decide what to monitor going forward.

The tools, by phase

You do not need an expensive stack to run a solid audit. The essentials:

• Google Search Console (free): the authoritative view of crawling, indexing, performance and Core Web Vitals, plus URL Inspection for single-page diagnosis. The backbone of the technical and on-page phases.
• An SEO crawler (Screaming Frog or similar): crawls the site to find broken links, redirects, duplicate/missing titles, orphan pages and more at scale.
• PageSpeed Insights (free): performance and Core Web Vitals for individual pages.
• Server logs (for large sites): the gold standard for seeing real crawl behaviour and budget waste.
• A backlink tool: for the off-page phase.
• Broad audit tools, StackOptic included, fold many technical, performance, SEO and AI-readiness checks into a single report, which is a fast way to get a prioritised overview before you drill in with the specialised tools.

A condensed audit checklist

• Verify Search Console access and capture a baseline (traffic, indexed pages, CWV, rankings).
• Crawl the site; list broken links, redirects, duplicate/missing titles, orphan pages, errors.
• Check the Pages report; confirm important pages are indexed and nothing valuable is excluded.
• Review robots.txt, sitemap and canonicals for correctness and consistency.
• Assess Core Web Vitals and find slow templates, not just slow pages.
• Confirm mobile-friendliness, HTTPS everywhere, and HTTP-to-HTTPS redirects.
• Audit titles, meta descriptions and heading structure.
• Review content quality, search-intent match and cannibalisation; use the Performance report.
• Check internal linking, orphan pages and anchor text.
• Validate structured data.
• Review the backlink profile and reputation.
• Prioritise every finding by impact vs effort and write an action plan.

Where to start

If a full four-phase audit feels daunting, start where the impact is highest and the effort lowest: indexing and crawlability. Open Search Console's Pages report and confirm your important pages are actually indexed and that nothing valuable is blocked or noindexed — accidental exclusions are common and devastating, and clearing them recovers visibility immediately. Next, crawl the site and fix broken pages and redirect chains. Then look at your slowest shared template, because fixing one template lifts every page that uses it. Those three moves — fix indexing, fix broken pages, fix the worst template — deliver most of the early value, and they give you a clean foundation before you move into the slower content and off-page work. Then turn the whole thing into a prioritised, recurring plan rather than a one-time effort.

Go deeper

• The technical detail: what is technical SEO and how to audit it.
• Diagnose indexing problems: how to fix crawl errors in Google Search Console.
• For large sites: what is crawl budget and how to optimize it.
• Extend it to AI: how to check if your site is ready for AI search.

Want a fast, prioritised overview before you dig in? Analyse any URL with StackOptic — one report covering technical SEO, performance, security and AI-readiness, free, no sign-up.