What is a technical site audit
Business owners often ask: "we're already publishing content and building links — why do we need yet another audit?" The answer is straightforward: if your site's foundation is cracked, nothing you build on top of it will hold. A technical audit is exactly the inspection of that foundation.
A technical audit is a systematic review of your website for errors that prevent search engines from properly crawling, understanding and ranking your pages. It has nothing to do with the quality of your copy or the strength of your backlinks — it's about whether Google can physically read your site the way it was intended.
From our practice: in eight out of ten clients who come to us with the problem "we have a site but no organic traffic," the audit surfaces something critical. Sometimes it's a small thing — a robots.txt file with one extra line that blocks an entire section. Sometimes it's more serious — after a redesign, the site accidentally switched from HTTPS back to HTTP without proper redirects, and Google spent months indexing the wrong version.
Why your business needs a technical audit
There's a common misconception: "if the site opens and looks fine, everything's okay." For a human visitor — maybe. For Google — definitely not.
A search engine crawler sees your site in a completely different way. It reads HTML, checks HTTP headers, measures load speed, looks at canonical tags and the robots.txt file. A beautiful visual design means nothing to it — what matters is structure and technical correctness.
Here's a concrete example. One of our clients — an online building materials store — had been investing in content marketing for years. Articles, product comparisons, buying guides. Traffic grew slowly and inconsistently. The audit revealed the issue: filter pages in the catalog were generating thousands of duplicate URLs without canonical tags. Google was spending its entire crawl budget on these duplicates and barely touching the pages with real content. After the fix, traffic started growing within 6 weeks — without a single new article.
A technical audit is necessary when: you have a new site (check before launch), after a redesign or domain migration, when traffic drops suddenly without an obvious reason, and regularly — like an oil change for your car.
Most common technical errors
Over eight years of SEO work, I've conducted more than 200 technical audits across sites of very different scales — from small corporate sites to e-commerce stores with hundreds of thousands of SKUs. There are errors that show up almost everywhere. Here they are, ordered from most critical to important-but-easy-to-miss.
Indexation issues
The first thing we check is whether Google can actually see your site at all. Open Google Search Console → Indexing → Pages → "Why pages aren't being indexed." If there are dozens or hundreds of pages with "Excluded" status, we start investigating why.
The most common reasons for indexation problems:
- Noindex on the wrong pages. This often happens after development — the developer adds noindex to prevent the staging site from being indexed, then forgets to remove it before launch. We've seen this more than once.
- Blocked in robots.txt. A
Disallow: /rule or overly broad directives that lock down entire site sections. - Orphan pages. Pages with no internal links pointing to them — Google simply can't find them, even if they're listed in the sitemap.
- Broken redirects. Redirect chains longer than two hops, or redirect loops — Google handles these poorly and often just stops following them.
Speed and Core Web Vitals
Since 2021, Core Web Vitals have been an official Google ranking factor. Three metrics are measured:
| Metric | What it measures | Good threshold |
|---|---|---|
| LCP | Load time of the largest element on screen | under 2.5 sec |
| INP | Site's response time to user interaction | under 200 ms |
| CLS | Layout shift during page load | under 0.1 |
The most common problem we see is unoptimized images. Product photos or hero banners weighing 3–5 MB, uploaded without compression and without lazy-loading. On mobile, a site like this takes 8–12 seconds to open, and LCP goes way beyond the threshold. Simply converting to WebP and adding loading="lazy" to below-the-fold images often improves LCP by 60–70%.
Another frequent cause of poor CLS is fonts loaded without font-display: swap. The page renders, text appears, then the font loads and replaces the fallback — shifting all content down the page. For Google, that's CLS. For users, it's frustrating.
Meta tags and duplicate content
Duplicates are one of the quietest SEO killers. They don't produce obvious errors, the site looks fine on the surface, but Google doesn't know which of two identical pages to show in search — and as a result shows neither, or shows the wrong one.
Where duplicates come from in practice:
- Pages accessible both with and without
www— two different URLs with the same content. - Versions with and without a trailing slash
/— again, duplicates. - Filters and sorting in e-commerce generate hundreds of URLs for the same product category.
- Pagination without canonical tags or rel="next/prev".
- Tag pages on a blog without noindex.
The solution is canonical tags. Every page should have <link rel="canonical" href="..."/> pointing to the authoritative version. Filter pages without unique content are best canonicalized to the parent category page.
Duplicate meta tags are a separate issue. If dozens of pages share the same title or description, it signals to Google that the content isn't unique. We check this in Screaming Frog by filtering for "Duplicate Page Titles" and "Duplicate Meta Descriptions."
Schema.org markup
Structured data isn't a mandatory requirement, but it's a powerful tool. Correct markup enables rich snippets in search results: star ratings, product prices, publication dates, FAQ blocks. A rich snippet takes up more space on screen and generates a higher CTR even at a lower ranking position.
The most common Schema.org errors: syntax mistakes in JSON-LD (a stray comma, a missing bracket), using outdated types (for example, Product without the mandatory name and offers fields), or markup that doesn't match the actual content on the page — Google can apply a manual penalty for this.
Need a technical audit of your site? Get a detailed report with priorities — delivered within 48 hours.
Tools for a technical SEO audit
The good news: the baseline tools for an audit are free. Here's the stack we use internally and recommend to clients.
Free tools
Google Search Console — the mandatory starting point. It shows real data on indexation, coverage, Core Web Vitals and Schema.org errors. If your site isn't connected to GSC, connect it right now — it's the first thing we do on any new project.
PageSpeed Insights — Core Web Vitals analysis by URL. Important: look at the Field Data section (real user data), not just the Lab Data (synthetic test). They often differ significantly — and Field Data is what Google actually uses for ranking.
Google Rich Results Test — Schema.org markup validation. It highlights errors and warnings, and shows what your rich snippet will look like in search results.
Screaming Frog SEO Spider (free version up to 500 URLs) — a crawler that scans your site the way Google does. Finds broken links, duplicates, missing meta tags, canonical issues and redirect problems.
Paid tools (for serious work)
Screaming Frog without the URL limit — £259/year, pays for itself on the first large-site audit. Ahrefs Site Audit — best for ongoing monitoring, with clear visualization of how error counts change week over week. Semrush Site Audit — a solid alternative, especially if you're already using Semrush for keyword research.
What a real audit looks like: step by step
When we take on a new project for an audit, the sequence is always roughly the same. I'm sharing our internal checklist.
Step 1. Basic indexation check. GSC → number of indexed pages vs. total pages on the site. If there's a significant gap, we start digging. In parallel, we check robots.txt and sitemap.xml for existence and correctness.
Step 2. Technical error analysis via Screaming Frog. We run a full crawl and filter for: 4xx errors, 5xx errors, redirect chains, duplicate titles and descriptions, missing H1 tags, images without alt text.
Step 3. Core Web Vitals. GSC → Core Web Vitals → check which URLs are flagged as "Needs Improvement" or "Poor." Run them through PageSpeed Insights to find the root cause for each metric.
Step 4. Schema.org check. We test the homepage, a typical service/product page and a blog article. Rich Results Test surfaces any errors. If the site uses multiple markup types, we check each one.
Step 5. Internal linking. We analyze orphan pages via Screaming Frog — pages with no internal links pointing to them. We check page depth: commercial pages shouldn't be more than 3 clicks from the homepage.
Step 6. Mobile version. Google's Mobile-Friendly Test for key pages. GSC → Mobile Usability — shows real problems on mobile devices from real traffic.
The audit output is a report with a prioritized task list: critical (fix immediately), important (fix this quarter), nice-to-have (fix when opportunity arises).
How often to run a technical audit
There's no single right answer — it depends on site size and pace of development. For small corporate sites, a full audit once per quarter and weekly GSC monitoring is enough. For large e-commerce stores with active development, monitoring needs to be continuous, because every deployment potentially breaks something.
There are situations that require an audit regardless of schedule: domain migration, CMS or hosting change, major redesign, or a sudden drop in traffic or rankings. In all of these cases, the first thing to do is a technical audit — to rule out a technical cause before investigating anything else.
Another useful practice is automated monitoring. Ahrefs and Semrush can both run audits on a schedule and email you when new critical errors appear. This isn't a replacement for a proper audit, but it's a solid early-warning system.
Summary: what to do after reading this
If you've never run a technical audit on your site, start right now with the free tools. Open Google Search Console, go to the Indexing section and see how many pages are excluded from the index and why. Then run PageSpeed Insights on your homepage and one commercial page. That takes 15 minutes and gives you an initial read on the site's health.
If your site is large, or you can see problems but can't identify the root cause, it's worth working with an expert. Not because "you can't figure it out yourself," but because an experienced SEO specialist completes a full audit in 4–8 hours rather than a week, and delivers a prioritized action plan on day one.
Technical SEO isn't the most exciting part of search optimization. But if the technical foundation isn't solid, every other effort — content, links, analytics — produces a fraction of its potential impact. Foundation first, everything else second.
