SEO Audit Checklist: How to Do a Website Audit Step by Step

An SEO audit checklist is only useful if it tells you what to fix first. Most business owners know they should learn how to do a website audit, and most keep putting it off, like a dentist appointment. Meanwhile the problems compound. Broken links pile up, pages get slower, content goes stale, rankings slip, and conversions leak away while you're busy with other priorities.

Your website isn't a "set it and forget it" asset. It has to keep up with search engine algorithms, real users on different devices, and your own changing business goals. An audit is the diagnostic scan that tells you what is actually happening under the hood, not what you assume is happening.

I've seen companies spend €50,000 on a redesign only to discover, six months later, that the new site had the same conversion problems as the old one. Nobody had audited the original site to understand what was broken, so they treated symptoms instead of causes. This guide shows how to do a website audit from start to finish: the five audit pillars, a 15-point checklist sorted by severity, the tools for each check, and what a professional audit costs.

A website audit is a structured evaluation of your site's technical crawlability, Core Web Vitals, information architecture, content quality, and conversion friction. It reveals hidden defects across code, search indexing, and user journeys, and sets clear priorities for traffic growth and revenue recovery. An SEO audit is the search-focused part of that work.

The process examines hundreds of data points: HTTP status codes and crawl errors, mobile rendering, page load times, meta tags, and content freshness. The goal isn't a massive spreadsheet of issues that makes everyone panic. It's a prioritized action plan that tells you where your time and budget will have the most effect.

Why should you care? Google's own data from 2016 found that 53% of mobile visits are abandoned when a page takes longer than three seconds to load. Speed shows up in revenue too: in the 2020 Milliseconds Make Millions study by Deloitte and Google, a 0.1-second improvement in mobile site speed was associated with 8.4% more retail conversions and 10.1% more travel conversions. Core Web Vitals also feed into Google's page experience signals. They rarely beat relevance, but between two equally relevant pages the faster one has the edge. A site that looks great on your office monitor but is slow, broken on mobile, or invisible to search engines costs you money every day.

The businesses that treat audits as a regular practice, not a one-time event, are the ones that consistently outperform their competitors online. It's not glamorous work, but it's some of the highest-ROI work you can do.

I've watched the same story play out dozens of times. A company launches a website, traffic looks decent for the first year, and then things start to slide. Organic traffic drops 15 to 20% over six months. The marketing team blames the algorithm. The sales team blames marketing. Nobody thinks to look at the website itself.

When we finally run an audit, we usually find the same patterns:

• Crawl errors that have been accumulating for months, preventing Google from indexing new pages
• Duplicate content created by URL parameters, pagination, or CMS misconfigurations
• Broken internal links from deleted pages that were never redirected
• Images without alt text, which hurts both accessibility and image search traffic
• Mobile usability issues that affect most of your visitors, since mobile devices account for roughly six in ten web visits worldwide, according to Statcounter

The financial impact is direct. If your site converts at 2% and you get 10,000 monthly visitors, even a small improvement, say from 2% to 2.5%, means 50 additional conversions per month. At a €200 average order value, that's €10,000 in monthly revenue you're leaving on the table. And that's a conservative scenario.

The longer you wait between audits, the more these issues compound. Technical debt on a website works like financial debt: it accrues interest. What could have been a quick fix six months ago might now require a partial rebuild.

If you're wondering how to do a website audit properly, the short answer is that it isn't one task. It's five evaluations that together give you a complete picture of your site's health. Run all five in order and you get a full diagnosis. Skip one and you're flying blind in that area, no matter how good your checklist looks on paper.

1. Technical crawlability and indexing. Can search engines crawl, render, and index your pages? This covers robots.txt directives, XML sitemaps, status codes, redirect chains, canonical loops, and structured data.

2. Core Web Vitals and real-user performance. How fast does the site load and respond for real visitors on real devices? This covers LCP, INP, and CLS from field data, server response time, image weight, and third-party scripts.

3. Information architecture and on-page SEO. Can people and crawlers find the right page for each query? This covers click depth, internal links, orphan pages, H1 to H3 nesting, keyword targeting, thin pages, and cannibalization. The content audit further down belongs to this pillar.

4. Security and infrastructure. Is the site safe to visit, and can you keep it that way without heroics? This covers SSL certificates, mixed content, CSP and HSTS headers, and outdated CMS cores, plugins, and dependencies.

5. Conversion and form friction. Do the visitors who arrive actually complete the action you want? This covers form usability on mobile, navigation clarity, accessibility, session recordings, and whether analytics events fire. The UX audit further down belongs to this pillar.

Each pillar can be reviewed on its own, but the value shows up when you read them together. A crawl error often explains a sudden drop in search traffic, and a slow INP score often explains why high-intent visitors leave without converting.

Here's the SEO audit checklist we use internally, condensed into a single table. Each row names the check, the tool that answers it, and a priority from P0 to P2, explained in the triage section at the end of this guide. Work through it pillar by pillar and tick off each row as you confirm it. That turns the five pillars above into concrete tasks you can assign to a person.

Here's a scenario that's more common than you'd think: a company publishes great content, but half its pages aren't even in Google's index. The content exists, but nobody can find it through search. That's a technical SEO problem, and it's exactly what this part of the audit catches.

Start with crawlability. Run your site through a crawler like Screaming Frog or Sitebulb. You're looking for 4xx client errors, 5xx server errors, redirect chains, and pages blocked by robots.txt. If search engine bots hit dead ends or waste crawl budget in redirect loops, those pages lose visibility regardless of content quality.

Next, check your indexation. Use Google Search Console to compare the number of URLs in your sitemap against the number Google has actually indexed. A big gap is a red flag. Common culprits include noindex tags accidentally left on production pages, canonical tags pointing to the wrong URLs, and duplicate content that leaves Google unsure which version to index.

Structured data is another area most sites neglect. Proper schema markup helps search engines understand your content and can earn you rich results: listings with star ratings, FAQ dropdowns, or product prices. Check your implementation with Google's Rich Results Test and fix any validation errors. Google's own Search Central documentation is the definitive reference if you run into edge cases.

Finally, review your internal linking structure. Every important page on your site should be reachable within three clicks from the homepage. Pages buried deep in your site hierarchy get less crawl budget and less authority. If you've recently redesigned your site or restructured your content, this matters even more, because broken internal links are one of the most common post-launch issues we find. For a deeper look at how corporate sites should structure their architecture, read our corporate website development guide.

Page speed isn't a vanity metric. It's a direct conversion lever. Google's 2017 mobile benchmark research found that as page load time rises from one second to three, the probability of a bounce increases by 32%. From one second to five, it increases by 90%.

Your performance audit should center on Core Web Vitals, Google's three metrics for page experience. Google counts a page as good when at least 75% of real visits meet each threshold:

• Largest Contentful Paint (LCP): how long until the main content of the page is visible. Good: 2.5 seconds or less.
• Interaction to Next Paint (INP): how quickly the page responds when someone clicks a button, taps the navigation, or types. Good: 200 milliseconds or less.
• Cumulative Layout Shift (CLS): how much the layout shifts unexpectedly while the page loads. Good: 0.1 or less.

Run your key pages through Google PageSpeed Insights and look at both the lab data and the field data (real user metrics). They often tell different stories. web.dev's Core Web Vitals guide explains exactly how each metric is measured.

The most common performance killers we find during audits:

• Unoptimized images: the number one offender. A single hero image saved as a 3MB PNG instead of a compressed WebP can add seconds to your load time.
• Too many third-party scripts: analytics, chat widgets, ad trackers, social media embeds. Each one adds HTTP requests and JavaScript execution time.
• No caching strategy: pages that should be cached aren't, so the browser downloads everything again on every visit.
• Render-blocking CSS and JS: stylesheets and scripts in the <head> that stop the page from rendering until they've fully loaded.

On most sites we audit, unused JavaScript and oversized images make up the bulk of avoidable page weight. Stripping that dead weight is often the fastest way to improve both performance and conversions.

The performance budget we set for client sites: server response under 200 ms, LCP under 2.5 s, INP under 200 ms, CLS under 0.1, and total page weight under 1.5 MB. Four fixes deliver most of the gains: serve images as WebP or AVIF at display size, defer non-essential scripts, self-host fonts with font-display: swap, and reserve explicit dimensions for late-loading elements.

Technical metrics only tell half the story. The other half is what real people experience when they land on your site. A UX audit evaluates the site from the visitor's point of view, and it belongs on your checklist next to the technical checks, because a fast, well-indexed page that frustrates visitors still loses the sale. Nielsen Norman Group's usability research is a good baseline if you want to go deeper.

Start with mobile testing on actual phones rather than browser simulations. Try to complete your top three conversion actions: buying something, sending an inquiry, finding the pricing. You will quickly spot touch targets that are too small, forms that are painful to fill in on a phone, and menus with too many layers.

Navigation analysis comes next. A first-time visitor should find the key answers within about 10 seconds. A main menu with more than seven items is a warning sign. Look at user flows in Google Analytics to find pages with unusually high drop-off.

Heatmap and session recording tools like Hotjar or Microsoft Clarity show how people actually behave. Where do they click? How far do they scroll? Where do they rage-click in frustration? That tells you about UX problems you can't see just by looking at your own site.

Don't forget accessibility. Run your site through an accessibility checker and aim for WCAG 2.2 AA. Since June 2025 the European Accessibility Act has made this a legal requirement for many consumer-facing online services in the EU, so it's no longer optional polish. The semantic HTML that screen readers depend on is also the structure search engines parse. Our UX/UI design services are built around this principle: interfaces that work for everyone, not just the average user.

Content audits are the part most businesses skip because they seem subjective. They aren't, once you approach them with data. Content sits in the third pillar, information architecture and on-page SEO, and it belongs on your checklist as much as crawl errors or Core Web Vitals scores. Every page should earn its place with a clear keyword target and a real match to search intent.

Map every indexed URL to a primary target keyword. If a page lacks a clear search intent, it either needs one or should be pruned. Thin pages under 300 words with no unique value dilute your domain's quality signals.

Look for content cannibalization: several pages targeting the same keyword. Search engines can't tell which page to rank, and usually none of them ranks well. Consolidate or differentiate. There's no middle ground.

Check your meta titles and descriptions. Are they unique on every page? Do they include your target keywords? Are they the right length (about 55 to 60 characters for titles, 150 to 160 for descriptions)? A surprising number of sites have duplicate or missing meta data across dozens of pages.

Review your content freshness. Pages with outdated statistics, old screenshots, or references to "2023 trends" tell both users and search engines that nobody maintains the site. Set a calendar reminder to review and refresh your top-performing pages at least every six months.

Finally, check content against search intent. Informational queries need educational depth, while transactional queries need transparent pricing and clear calls to action. When content matches intent, conversion rates hold up.

You don't need to audit everything by hand, because each part of the checklist maps onto an established tool. The right toolkit automates repetitive checks and surfaces anomalies that manual reviews miss, turning days of inspection into a few focused hours. Here is our core stack:

For technical SEO:

• Screaming Frog SEO Spider: the industry standard for site crawling. The free version handles up to 500 URLs per crawl and catches broken links, redirect chains, duplicate content, missing meta data, and dozens of other issues in one pass.
• Google Search Console: free and essential. It shows how Google sees your site: indexation status, crawl errors, Core Web Vitals data, and search performance.

For performance:

• Google PageSpeed Insights: combines Lighthouse lab data with real-world field data from the Chrome User Experience Report.
• GTmetrix: detailed waterfall charts that show exactly what's slowing your pages down.

For UX and behavior:

• Hotjar or Microsoft Clarity: heatmaps, session recordings, and user feedback. Clarity is completely free and surprisingly capable.
• Google Analytics 4: for tracking user flows, finding high-exit pages, and measuring conversion paths.

For content and SEO strategy:

• Semrush or Ahrefs: both offer site audit tools alongside keyword research, competitor analysis, and backlink monitoring. If you can only pick one, either will do the job.

For accessibility:

• WAVE: a free browser extension that flags accessibility issues directly on your pages.

Owning every tool matters less than knowing what to do with the data. A tool can tell you that a page has a CLS score of 0.35. It can't tell you whether fixing it should be priority #3 or priority #30 on your roadmap. That takes experience and business context.

There's no single right answer to how often you should run through your SEO audit checklist. It depends on how much revenue rides on the site and how often it changes. The cadence below works for most businesses; adjust it to your site's size and to how often you publish or ship changes:

Quarterly: quick health check. Run a technical crawl, check Core Web Vitals, review Search Console for new errors, and scan for broken links. This takes a few hours and catches problems before they snowball. Think of it as an oil change.

Twice a year: deeper review. Add UX analysis, a content freshness review, and competitive benchmarking. Pull heatmap data and compare conversion metrics against the previous period.

Annually: full audit. All five pillars, top to bottom. Review your entire content inventory, test every user journey, benchmark against competitors, and build a prioritized roadmap for the coming year.

After major releases: mandatory. Redesigns, CMS migrations, and major navigation changes need an audit before and right after launch to protect organic rankings.

Match the frequency to your release pace: an e-commerce store shipping weekly needs monthly technical checks, while a corporate service site does fine on a quarterly rhythm.

Can you audit your own website? Yes. The checklist above will get a technically minded person most of the way there. Whether you should, or whether a professional website audit service is the smarter call, depends on your situation: the skills in your team, the size of the site, and how much it costs you to get the priorities wrong.

DIY works well when:

• Someone on your team has technical SEO knowledge
• Your site is relatively small (under 100 pages)
• You're doing routine quarterly checks
• You mainly need quick wins and obvious issues

Hiring a professional makes sense when:

• You're planning a website redesign or migration and need a pre-project baseline
• Your traffic or conversions have dropped and you can't figure out why
• Your site is large or technically complex
• You need an outside view (it's hard to see your own blind spots)
• You want a prioritized action plan, not just a list of problems

A professional audit goes deeper than tools alone. It includes competitive analysis, conversion path evaluation, and recommendations tied to your business goals rather than generic best practices. See our services for how we approach audit-driven website improvement.

Even if you hire someone, understand the process well enough to judge their work. An auditor who hands you a 200-page report without clear priorities and next steps hasn't done the job.

What an SEO audit costs depends on scope more than page count: how many templates, languages, and integrations the site has, and whether you get a raw crawl export or a prioritized fix plan with implementation notes. One-off quotes from European agencies usually fall into three bands, and the middle band covers most company websites.

• €500 to €1,500: small sites (roughly up to 50 pages) with a technical crawl, an on-page review, and a short fix list. At the low end, ask whether a person reviews the tool output at all.
• €1,500 to €4,500: mid-size company sites, multilingual sites, or small shops. This band should cover all five pillars, keyword and competitor context, and a P0 to P2 action plan.
• €4,500 and up: large shops, portals, migrations, and JavaScript-heavy platforms. Enterprise audits with log-file analysis and international SEO often reach five figures.

At Vezert you can start with a free 30-minute SEO audit. Ongoing audits are part of our SEO retainer from €2,500 per month, which includes a full technical audit and Core Web Vitals recommendations. Rates for design and development work are on our pricing page. Whoever you hire, compare quotes by deliverables: which pillars are covered, whether findings are prioritized, and whether someone walks you through the results.

An audit is only valuable if you act on it. I've seen too many reports gather digital dust in someone's inbox after a team worked through the entire checklist and produced a beautifully organized document nobody opened again. Here's how to make sure yours leads to real improvements instead of becoming shelfware.

Triage every finding as P0, P1, or P2. Not every issue needs fixing this week. We use three severity levels, the same ones as in the checklist table:

• P0 (Blocker): the issue stops pages from being indexed, breaks a conversion path, or creates a security risk. Examples: an accidental noindex on a service page, an expired SSL certificate, a contact form that won't submit on mobile. Fix these within one to two weeks.
• P1 (High risk): the issue costs measurable rankings or leads, but nothing is broken. Examples: LCP above 2.5 s on key landing pages, a sitemap listing far more URLs than Google indexes, missing security headers. Schedule these for the next 30 to 60 days.
• P2 (Optimization): polish that improves quality but won't move revenue on its own. Examples: schema on secondary templates, orphan blog posts, heading clean-up. Add these to the backlog and batch them.

When a finding sits between two levels, ask one question: does it cost traffic or leads today? If it does, move it up.

Assign ownership. Every action item needs a named owner and a deadline. "The dev team will look into it" is not an action plan.

Track the impact. Before you fix anything, record your baseline: organic traffic, bounce rate, conversion rate, Core Web Vitals scores. Measure again 30, 60, and 90 days after the changes go live. That's how you prove ROI and make the case for recurring audits.

Build it into your process. The approach that works best is treating website health the way you'd treat product quality, as a continuous concern, not a periodic project. Set up automated monitoring for uptime, performance, and crawl errors. Review key metrics monthly. And schedule your next audit before the last one's findings go stale.

Your website is the sales engine that works for your business around the clock. A regular website audit keeps it running at full capacity. Our SEO services and website maintenance plans include continuous site-health audits. Start with a conversation about your site's health to find and fix your most valuable growth opportunities.