Technical SEO audit in Lyon — Find and fix the hidden issues holding your website back

What is a technical SEO audit?

Technical SEO vs on-page SEO: two sides of an optimised website

SEO splits into two complementary branches. On-page SEO covers the visible content of your pages: title tags, descriptions, copy, images, internal links. Technical SEO deals with the invisible infrastructure that lets Google discover, crawl and index your pages properly. Without a solid technical foundation, even the best content stays invisible to search engines. A technical SEO audit examines that foundation in depth.

The technical errors that make a site drop in Google

The most common technical issues we find in our audits in Lyon include: pages unintentionally blocked by the robots.txt file, cascading 404 errors on key pages, misconfigured canonical tags creating duplicate content, a missing or outdated XML sitemap, chains of 301/302 redirects that dilute link equity, excessive load times penalised by Google, and missing or incorrect Schema.org structured data. Each of these errors is a measurable drag on your rankings.

Who needs a technical SEO audit?

Any website owner who is seeing organic traffic stall or fall, who is preparing a redesign, who has just migrated to a new CMS, or who has never had their site audited. Small businesses and SMEs in Lyon and across Auvergne-Rhône-Alpes that find competitors outranking them on Google have a particular interest in quickly identifying the technical causes of the gap.

The 10 areas checked in our technical SEO audit

1. Crawlability and indexing

We check that Google can discover and index all of your important pages. Analysis of the robots.txt file, the XML sitemap, noindex directives, crawl budget and index coverage in Google Search Console. If Google cannot crawl your pages, they will never exist in search results.

2. URL structure and redirects

Analysis of canonical URLs, detection of 301/302 redirect chains, checks on URL consistency (trailing slashes, parameters, capitals). A clean URL structure makes crawling easier for Google and improves the user experience.

3. Core Web Vitals and performance

In-depth measurement of LCP (Largest Contentful Paint), INP (Interaction to Next Paint), CLS (Cumulative Layout Shift), TTFB and FCP. These metrics have been Google ranking factors since 2021. Explore our Core Web Vitals optimisation service to get your scores into the green.

4. Schema.org structured data

Review and optimisation of JSON-LD markup: LocalBusiness, FAQPage, Service, BreadcrumbList, Organization. Structured data makes your pages eligible for rich results in Google (rich snippets), which significantly increase click-through rates. For local businesses, optimised LocalBusiness markup strengthens consistency with your Google Business Profile listing.

5. Meta tags and H1–H6 structure

Audit of every title tag, meta description, H1 to H6 heading structure and image alt attribute. Each page should have a single H1 containing the main keyword, properly nested headings and descriptions of 120 to 130 characters for optimal display in the SERPs.

6. Internal linking and page depth

Analysis of internal PageRank distribution, orphan pages and navigation depth. Well-optimised internal linking guides Google towards your most strategic pages and makes the whole site easier to crawl.

7. Mobile-first and device compatibility

Google primarily indexes the mobile version of your site (mobile-first indexing). We check mobile rendering, tap target sizes, text legibility and the viewport meta tag to ensure a flawless experience on every device.

8. HTTPS, security and trust signals

Checks on the SSL certificate, mixed content (HTTP/HTTPS) and security headers (HSTS, CSP, X-Frame-Options). Security is a trust signal for Google and for your visitors. Find out more about our web security and GDPR service.

9. Hreflang and internationalisation

For multilingual sites, we check that hreflang tags are implemented correctly, that alternate URLs are consistent and that there are no conflicts between language versions.

10. Toxic backlink analysis

Audit of your inbound link profile to identify low-quality backlinks that could harm your rankings. Where necessary, we prepare a disavow file to submit to Google.

The tools behind our technical SEO audit

Semrush Site Audit

A full site crawl with automatic detection of more than 140 types of technical error. Semrush gives us an overall health score and recommendations prioritised by SEO impact.

Google Search Console

Data straight from Google: index coverage, crawl errors, field Core Web Vitals, search performance and manual actions.

Screaming Frog SEO Spider

A page-by-page technical crawl extracting every tag, redirect, internal link and resource. Essential for in-depth audits of large websites.

Lighthouse and PageSpeed Insights

Core Web Vitals measured in both lab and field conditions. Our own site scores 100/100 for SEO and 87/100 for performance in Lighthouse, figures published on its case study page — we apply the same standards to your projects.

What you receive after the audit

A 20- to 50-page PDF report

A comprehensive document illustrated with screenshots, charts and detailed analysis for every area checked. No needless jargon — each issue is explained clearly, along with its impact on your rankings.

Prioritised fix list (impact/effort)

Every fix is placed in an impact/effort matrix so you can prioritise the most cost-effective actions. Quick wins (high impact, low effort) are flagged first for fast results.

60-minute debrief call

A one-hour call with our SEO expert to walk through the report, answer your questions and agree the action plan together. We explain every recommendation in plain language.

30/60/90-day fix plan

A realistic schedule for implementing the fixes identified, whether you handle them in-house or entrust them to us. Complement your audit with our full website audit for a 360° view of your online presence.

Why choose KAYZEN for your technical SEO audit?

We are not an automated tool churning out a standardised report. Every KAYZEN technical SEO audit is carried out manually by an expert who interprets the data, identifies root causes and makes recommendations tailored to your business context. Our own site achieves an SEO score of 100/100 — we hold your projects to exactly the same standards.

Based in Lyon's 9th arrondissement, we support small businesses and SMEs in Lyon and across Auvergne-Rhône-Alpes with a pragmatic approach: realistic fixes, a workable schedule and measurable ROI. Explore our complete SEO service and our Core Web Vitals optimisation service too.