WEBSITE PERFORMANCE AUDIT

Complete assessment,
prioritised action plan.

A documented assessment that distinguishes field data, lab tests and manual checks. Each finding includes its context, limitations and action priority.

Generate my checklist Explore the audit areas

Illustration of a web performance assessment. — Identify what slows your website down. Editorial illustration.

CrUX

Field data

Where available

Lab

Controlled tests

Lighthouse and waterfall

Review areas

Scope tailored to the website

I / E

Prioritisation

Estimated impact and effort

INTERACTIVE TOOL

What should you audit
first on your website?

Answer 4 questions about your website. The tool prepares a list of areas to examine. It does not assess their severity or impact without measurement.

Your profile:

CMS / framework

Website age

Website size

Performance monitoring in place?

Your priority checklist

Detected profile: WordPress business website, 1-3 years old

Recommended audit: Complete audit (€1,800)

Request

Illustrative guidance only. The scope, priorities and conclusions are established after scoping and measurement.

Scope

8 areas, a contextualised assessment.

Relevant checks are tailored to the website’s stack, access, templates and objectives.

The visual guide

Bring the evidence together while keeping measurement contexts distinct

Field

Available CrUX data reflects real visits.
Lab

Controlled tests help diagnose a page.
Manual review

Keyboard, form and user journey checks complement the tools.

The report specifies access, templates tested and the limitations of its findings.

Core Web Vitals (LCP, CLS, INP)

CrUX field data where available, supplemented by Lighthouse lab tests. The two contexts remain distinct in the report.

Technical SEO

Crawling, indexing, sitemap, robots.txt, canonical, hreflang and Schema markup.

WCAG accessibility

Contrast, HTML semantics, ARIA, keyboard navigation and manual testing. Applicable legal requirements are analysed separately.

Security

HTTP headers (CSP, HSTS), CMS versions, vulnerable plugins and SSL.

Privacy and tracking

Inventory of trackers, consent mechanisms and data flows. The technical audit does not replace legal advice.

Architecture and code

Stack, dependencies, technical debt, scalability and maintainability.

UX and conversion

Heatmaps, typical journeys, friction, A/B testing setup and forms.

Mobile and responsive design

Tests on real devices, touch interaction, viewport and touch targets.

Method

From measurement to decision.

01

Scoping

Objectives, context, available access and priority indicators.

Scope
02

Measurement and review

Field data, lab tests, crawling, code review and manual checks within the agreed scope.

Assessment
03

Report + recommendations

Findings with supporting evidence, limitations and impact/effort priorities.

Decisions
04

Presentation

Presentation of findings, questions and decisions on next steps.

Handover

Transparency

What is included,
and what is not.

Included in the price

Scoping brief defining objectives and scope
Technical review across the 8 stated areas
Mobile and desktop Lighthouse tests on selected pages
Waterfall analysis where relevant
SEO crawl adapted to website size
Code and stack review where access allows
Documented report with screenshots and measurement context
Prioritised impact/effort action plan
Video presentation and Q&A
Indicative quotation if optimisation is needed

Optional or available separately

Implementation of recommendations (quoted separately)
Visual redesign (separate service)
A/B testing setup (optional extra)
Qualitative UX user testing (additional option)
Monthly follow-up after the audit (Continuous Performance)

Investment

Three audit packages.

Express audit

Business website or simple e-commerce store

950 €

Excluding VAT · Scope to be confirmed

Review of the 8 areas
Selected key pages
Summary report
Presentation
Prioritised action plan

Extended format

Complete audit

Established SME, e-commerce, multilingual

1 800 €

Excluding VAT · Scope to be confirmed

In-depth review of the 8 areas
Representative page sample
Technical crawl
Documented report
Findings presentation and questions

Premium Audit

B2B website, platform, marketplace

From €3,500

Excluding VAT · On quotation

Scope adapted to complexity
Multiple languages or markets
Optional user testing
Bespoke report
Team findings workshop

Indicative prices excluding VAT. Scope, schedule and final price confirmed in the quotation. VAT applies according to your situation.

Frequently asked questions

All about the performance audit.

What is a complete performance audit?

Our audit combines Core Web Vitals, technical SEO, accessibility, security, privacy, architecture, UX and mobile. Field data is distinguished from lab tests and supplemented with manual checks. The scope and deliverables are confirmed before the assignment. For search visibility, our advice on <a href='/blog/reussir-audit-seo/' class='text-kanexio-cyan hover:underline'>running a successful SEO audit of your website</a> complements this assessment.

How much does a performance audit cost in Brussels?

The packages shown start at €950 excluding VAT. The final price depends on factors including the number of templates and languages, available access and the depth of analysis required. The scope is confirmed in the quotation, with no promise of a score, ranking or financial return.

What is the difference between an audit and optimisation?

An audit measures, documents and prioritises issues without changing the website. Optimisation implements the selected fixes. You can entrust this work to your team or another provider, or ask us for a separate quotation for <a href='/creation-site-web/performance/' class='text-kanexio-cyan hover:underline'>performance optimisation</a>.

How soon will I receive the audit report?

The schedule depends on the website’s size, languages, access availability and required tests. It is set out in the quotation before work begins. Field measurement may also need a different observation window from a one-off lab test.

Does the audit require admin access to my website?

An initial analysis can be carried out using public pages. Temporary access may nevertheless be needed to examine the configuration, plugins, caching or code. The report always distinguishes what was verified from what could not be checked. A confidentiality agreement can be arranged.

Does the audit cover WCAG accessibility?

Yes, the scope includes WCAG-based checks and manual testing. The results describe the criteria tested and their limitations: an automated tool or a sample of pages cannot establish full compliance. The applicable legal obligations also depend on the service and organisation concerned.

What happens after the audit?

You receive a prioritised action plan and can manage implementation internally, appoint another provider or request a quotation from us. A <a href='/creation-site-web/maintenance/' class='text-kanexio-cyan hover:underline'>website maintenance</a> contract can then help maintain technical quality. There is no obligation to continue with us.

Performance audits in Uccle, Ixelles, Saint-Gilles, Etterbeek, Woluwe-Saint-Pierre and 15 other municipalities.

A free first look at your website.

A scoping conversation and a few public checks to identify the priority questions. This initial review does not replace a complete audit.

Request the free audit View the case studies