Technical SEO Audit: A Practical Walkthrough With Free Tools

Technical SEO Audit: A Practical Walkthrough With Free Tools#

A technical SEO audit is the part of an audit that decides whether any of your other work even gets a chance to matter. You can write the best page on the internet, but if a search engine cannot crawl it, render it, or index it, none of that effort shows up in search results. This walkthrough runs the technical pass step by step, with a free tool for each stage and a clear order for fixing what you find.

The goal here is not to drown you in a 200-line crawl export. It is to check the handful of things that genuinely move rankings, understand why each one matters, and leave with a prioritised list. At the end, we will connect the technical layer to the lead-generation layer that most audits never reach, because a perfectly indexed page that converts nobody is still a commercial loss.

Start with crawlability: can search engines reach the pages#

Crawlability is the first question because everything downstream depends on it. If a crawler cannot reach a page, the page might as well not exist. There are a few common ways a site quietly blocks itself.

Open the robots.txt file first. Type the domain followed by /robots.txt into your browser and read it. You are checking that it does not accidentally disallow important sections. A single stray Disallow: / can hide an entire site from search. It happens more than you would think, usually left over from a staging environment that went live without anyone removing the block.

Next, look at how the navigation is built. Click through the main menu and a few in-content links. Important pages should be reachable within a click or two of the homepage. Pages that nothing links to, called orphan pages, are hard for crawlers to discover and tend to underperform. A free-tier crawl with a desktop tool like Screaming Frog will surface internal links, redirects and response codes in one pass, which is the fastest way to see the site the way a crawler does.

Finally, watch for crawl traps. These are patterns that generate near-infinite URLs, such as faceted filters, calendar pages, or session parameters appended to every link. They waste crawl budget on junk and bury the pages you actually want indexed. If a site: search returns thousands of results for a site with a few dozen real pages, a crawl trap is the usual cause.

Check indexation: is the site actually in the index#

Crawlable is not the same as indexed. A page can be reachable and still be left out of the index. Indexation is where a lot of invisible traffic loss hides.

The fastest free check is the site: operator. Search site:example.com and look at two things. First, do the important pages appear at all. If a key page is missing, that is your highest-priority finding, because an unindexed page earns zero search traffic no matter how good it is. Second, does the rough count of results match the number of real pages. A big mismatch in either direction signals a problem: too few means pages are being excluded, too many means duplicate or parameter URLs are bloating the index.

For sites you own, Google Search Console is the ground truth. The Pages report under Indexing tells you exactly which URLs are indexed and which are excluded, and why. Pay attention to the common exclusion reasons: “Crawled, currently not indexed” often points to thin or duplicate content, “Discovered, currently not indexed” can mean crawl budget or quality issues, and “Duplicate without user-selected canonical” points straight at a canonical problem you can fix. The URL Inspection tool lets you check a single page and request indexing once you have fixed it.

Measure Core Web Vitals: how the page performs for real users#

Core Web Vitals are Google’s set of real-world performance metrics, and they are both a ranking factor and a conversion factor. Run the homepage and one or two key internal pages through PageSpeed Insights, which is free and reports field data from real visitors where there is enough traffic, plus lab data from Lighthouse.

The three metrics to read are Largest Contentful Paint, which measures how long the main content takes to appear, Interaction to Next Paint, which measures responsiveness to input, and Cumulative Layout Shift, which measures how much the page jumps around as it loads. Do not fixate on the single overall score, which is blunt and can swing between runs. Read the specific opportunities the tool lists instead: oversized images, render-blocking scripts, layout shift from images without dimensions. Those are concrete, fixable items.

Performance is one of the few places where the SEO audit and the conversion audit overlap directly. A slow page sheds rankings and visitors at the same time, which is why it is worth getting right rather than treating it as a vanity score.

Validate structured data: help search engines understand the page#

Structured data is markup that tells search engines what a page is about in a machine-readable way: that this is an article, a product, a local business, a set of FAQs. It does not guarantee rich results in search, but it makes them possible, and rich results can meaningfully improve click-through.

Use Google’s Rich Results Test and the Schema Markup Validator, both free. Paste a URL or the markup itself and check two things: that the structured data is valid with no errors, and that it matches what the page actually shows. Markup that claims things the page does not contain is a quality problem, not a shortcut. Start with the schema types that fit the site, such as Organization, LocalBusiness, Article, Product or FAQPage, and fix any errors before adding more types. Clean, accurate markup on the page types that matter beats a scattershot of half-valid schema everywhere.

Audit redirects and broken links: stop leaking authority#

Redirects and broken links are where link authority and crawl budget quietly drain away. A crawl export makes this layer easy to read.

Look for a few specific problems. Redirect chains, where one URL redirects to another that redirects again, slow crawling and dilute the signal passed along; collapse them to a single hop. Redirect loops, where two URLs point at each other, trap crawlers entirely. Broken internal links, returning 404s, waste crawl budget and frustrate visitors. And check that you are using the right redirect type: a permanent move should be a 301, not a temporary 302, so that ranking signals transfer.

Pay particular attention to any recent migration. Moving to https, switching domains, or restructuring URLs without mapping old paths to new ones is one of the most common causes of a sudden traffic drop. Every old URL that earned links or rankings needs a 301 to its closest new equivalent.

Review sitemaps and canonicals: tell search engines what matters#

The last two technical items are about giving search engines clear instructions, rather than leaving them to guess.

Your XML sitemap should list the canonical, indexable URLs you want in the index, and nothing else. It should not include redirected URLs, 404s, noindexed pages, or non-canonical duplicates. Open the sitemap, spot-check a handful of URLs, and confirm they return 200 and are the versions you actually want ranked. Then submit it in Search Console and watch the coverage, which tells you how many submitted URLs were indexed.

Canonical tags resolve duplication by naming the preferred version of a page. Check that each important page points its canonical at itself, that duplicate or parameterised versions point at the canonical original, and that you are not accidentally canonicalising everything to the homepage, which is a surprisingly common and damaging mistake. The “Duplicate without user-selected canonical” status in Search Console is your shortlist of pages to fix here.

How to prioritise the fixes#

A technical audit produces a list, and the temptation is to start with whatever is easiest. Resist it. Sort by impact instead, roughly in this order:

1. Indexation blockers. Anything keeping important pages out of the index. Zero indexation means zero traffic, so this is always first.
2. Crawl waste and broken redirects. Crawl traps, redirect chains and loops, and 404s on linked pages. These dilute authority and waste budget across the whole site.
3. Core Web Vitals. Slow loads and layout shift, especially on mobile and on your highest-traffic pages, where the cost compounds.
4. Structured data and canonicals. Valid schema on the right page types and clean canonical tags. Important, but polish rather than emergency for most sites.

Fixing in this order means the highest-leverage problems get solved while attention is fresh, and you avoid the trap of shipping ten cosmetic fixes while a noindex tag keeps your money page out of search.

The layer most technical audits skip#

Here is the honest limit of a technical SEO audit. It can confirm that a site is crawlable, fast and correctly indexed, and tell you nothing about whether that traffic turns into customers. A page can pass every check above and still be a dead end: no clear next step, no way to capture an interested visitor, no follow-up to bring them back.

That conversion layer is the one tied to revenue, and it is the one our free tool grades. The 12-point website audit scorecard walks the capture, follow-up, trust and performance gaps that technical tools ignore, and turns them into a named, prioritised list. If you also prospect for clients, the lead scoring calculator helps you decide which sites are worth auditing in the first place.

A complete picture needs both. Run the technical pass above to make sure visitors can arrive, then run the free SEO audit walkthrough and the scorecard to make sure they convert once they do. For a faster cross-check on individual issues, the platform behind this tool at Inflowave is built around the same idea: visibility is necessary, but it is the lead-gen layer that pays.