Website Technical Performance Audit
Audit of Core Web Vitals, third-party tag load impact, and rendering bottlenecks, with a prioritised fix list and expected gains per recommendation.
Audit of your Core Web Vitals and third-party tag load impact, with a prioritised fix list and expected performance gains per recommendation.
Sites where Lighthouse scores are suffering despite standard optimisations, and the suspected root cause is third-party scripts and marketing tags.
- 6-12 hours, 5-10 representative page templates
- LCP, INP, and CLS measured per template
- Every tag measured for its individual performance cost
- Expected gains stated per recommendation
Overview
How to know if you need a Website Technical Performance Audit
- Your Lighthouse or CrUX scores are poor despite having already optimised images, fonts, and CSS.
- You suspect your marketing tag stack is contributing to slow page load but have no data to confirm which tags are responsible or by how much.
- LCP, INP, or CLS is failing in your Core Web Vitals report and the cause is not obvious from standard tooling.
- You have recently added several third-party scripts and page speed has declined since, but you do not know which script is the primary cause.
- A client, stakeholder, or SEO team has flagged Core Web Vitals as a business concern and you need specific, evidence-backed fixes.
What the Website Technical Performance Audit covers
- Core Web Vitals measured per representative page template on both desktop and mobile under realistic network conditions: LCP, INP, and CLS.
- Every third-party tag measured for its individual contribution to LCP, INP, and CLS.
- Render-blocking analysis: tags making synchronous network requests, blocking the main thread, or loading in a way that delays paint.
- Tag loading strategy review: which tags are loaded in the head, which are deferred, and whether current loading order is correct.
- Prioritised fix list with expected performance gains per recommendation so you know where to invest first.
Website Technical Performance Audit outcomes
- A baseline report showing current Core Web Vitals scores per page template on desktop and mobile.
- A third-party tag performance impact analysis showing which tags cost the most and why.
- A prioritised fix list with expected performance gains per recommendation.
Website Technical Performance Audit scope and hours
- 6-12 hours.
- 5-10 representative page templates in scope. Templates are agreed at scoping based on traffic volume and commercial importance.
- Both desktop and mobile tested.
- Delivery typically within 1-2 weeks after scoping is confirmed.
What makes our Website Technical Performance Audit different
- We measure every tag individually for its performance cost, not just report an overall Lighthouse score.
- Expected gains are stated per recommendation. You know which fixes will move the needle before you invest development time in them.
- Testing is done under realistic network conditions, not just on an unthrottled desktop connection.
- This audit focuses specifically on the tag stack and rendering pipeline, not general web performance advice you could get from any Lighthouse report.
More Audits services
View all Audits servicesWant to try before you commit?
- Looking to try out Beluacode but not sure about it? You can always ask us for a free audit.
- Free, no strings attached. We deliver the results and wish you a great day.
- You will not be forced to talk to us, no call needed to release the results :)
How we deliver Website Technical Performance Audit.
A structured process built around your stack, your team, and your data.
Baseline measurement
Core Web Vitals are measured on each representative page template under desktop and mobile conditions with realistic network throttling.
Tag performance profiling
Each third-party tag is measured for its specific contribution to LCP, INP, and CLS, isolating tag impact from overall page weight.
Render-blocking analysis
We identify tags making synchronous network requests, blocking rendering, or competing for the main thread during page load.
Fix prioritisation
Issues are ranked by expected performance gain, with specific recommendations for loading strategy, async deferral, and tag removal candidates.
Report delivery
A prioritised findings report is delivered with before/after estimates for each recommendation so you know where to invest first.
Frequently Asked Questions
What are Core Web Vitals?
How do you measure the performance cost of individual tags?
Will you fix the issues found?
Do you test on real devices or just emulation?
What if our site has no GTM or tag manager?
Pairs well with
Free Generic Tracking Audit
A high-level review of your overall tracking setup: event coverage, obvious configuration errors, attribution quality, and the highest-impact quick wins across your analytics and ad platforms.
Free GTM Container Audit
A surface-level review of your Google Tag Manager container: tag count, obvious duplicates, missing consent triggers, broken references, and the highest-impact issues. Delivered as a written summary.
Free Consent Mode Audit
A basic review of your Google Consent Mode v2 implementation: whether it is configured, which mode is active (Basic or Advanced), and whether consent states appear to be respected by your key tags.
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