© 2026 The Cogworks LTD
© 2026 The Cogworks LTD
© 2026 The Cogworks LTD
Website Carbon and Performance Audit
Faster pages. Lower costs. Smaller footprint.
A Cogworks Website Carbon and Performance Audit measures your website's speed, page weight, hosting efficiency, and carbon impact across representative pages. You receive a performance playbook with scenario modelling, cost-saving projections, and a prioritised action plan, so you know exactly where to invest for the biggest improvement in speed, cost, and sustainability.
increase in bounce probability when load time rises from 1 to 3 seconds
increase in bounce probability when load time rises from 1 to 3 seconds
increase in bounce probability when load time rises from 1 to 3 seconds
of mobile visitors leave if a page takes over 3 seconds to load
of mobile visitors leave if a page takes over 3 seconds to load
of mobile visitors leave if a page takes over 3 seconds to load
of mobile pages take over 5 seconds to load visual content
of mobile pages take over 5 seconds to load visual content
of mobile pages take over 5 seconds to load visual content
Digital Consultancy Services
Who it’s for
This audit is for you if: your website feels slow but you don't know what's causing it. Your hosting costs keep rising without matching improvement. You have sustainability or ESG commitments and need to understand your site's environmental impact. Or you want a clear, quantitative baseline before investing in optimisation.
How it works
1
Tell us about your site
A short questionnaire to understand your goals, hosting setup, and known performance concerns. Followed by a walkthrough to confirm the key page types to assess and any infrastructure context we need.
2
We measure, model and benchmark
We run Lighthouse audits and our own in-house carbon calculator across representative page types, break down page weight by asset, review hosting and delivery efficiency, assess third-party script impact, and validate lab findings against real-world Core Web Vitals. Where the data supports it, we model what changes under different optimisation scenarios.
3
You get the full picture
A playbook walking you through current performance reality, cost and carbon implications, and scenario-based projections. Every finding framed as a business decision with quick wins and structural improvements clearly separated.
1
Tell us about your site
A short questionnaire to understand your goals, hosting setup, and known performance concerns. Followed by a walkthrough to confirm the key page types to assess and any infrastructure context we need.
2
We measure, model and benchmark
We run Lighthouse audits and our own in-house carbon calculator across representative page types, break down page weight by asset, review hosting and delivery efficiency, assess third-party script impact, and validate lab findings against real-world Core Web Vitals. Where the data supports it, we model what changes under different optimisation scenarios.
3
You get the full picture
A playbook walking you through current performance reality, cost and carbon implications, and scenario-based projections. Every finding framed as a business decision with quick wins and structural improvements clearly separated.
1
Tell us about your site
A short questionnaire to understand your goals, hosting setup, and known performance concerns. Followed by a walkthrough to confirm the key page types to assess and any infrastructure context we need.
2
We measure, model and benchmark
We run Lighthouse audits and our own in-house carbon calculator across representative page types, break down page weight by asset, review hosting and delivery efficiency, assess third-party script impact, and validate lab findings against real-world Core Web Vitals. Where the data supports it, we model what changes under different optimisation scenarios.
3
You get the full picture
A playbook walking you through current performance reality, cost and carbon implications, and scenario-based projections. Every finding framed as a business decision with quick wins and structural improvements clearly separated.
What we look at
1
Multi-page performance and page weight analysis
Lighthouse audits across representative page types: homepage, content, conversion, capturing Core Web Vitals, scores, and a full asset breakdown. We identify systemic vs page-specific issues and which templates carry the most weight.
2
Hosting, delivery and infrastructure efficiency
A review of your hosting provider, CDN usage, caching behaviour, compression, and image delivery, answering whether issues are caused by the site or the environment, and what that environment is costing you.
3
Real-world performance signals
Where field data is available, we compare lab results against actual user experience, segmented by device, to validate findings and flag where lab results may be misleading.
4
Third-party tool cost and impact review
An inventory of every third-party script, grouped by purpose, measured by load and execution cost, identifying high-cost, low-value tools that undermine performance without delivering proportional business value.
1
Multi-page performance and page weight analysis
Lighthouse audits across representative page types: homepage, content, conversion, capturing Core Web Vitals, scores, and a full asset breakdown. We identify systemic vs page-specific issues and which templates carry the most weight.
2
Hosting, delivery and infrastructure efficiency
A review of your hosting provider, CDN usage, caching behaviour, compression, and image delivery, answering whether issues are caused by the site or the environment, and what that environment is costing you.
3
Real-world performance signals
Where field data is available, we compare lab results against actual user experience, segmented by device, to validate findings and flag where lab results may be misleading.
4
Third-party tool cost and impact review
An inventory of every third-party script, grouped by purpose, measured by load and execution cost, identifying high-cost, low-value tools that undermine performance without delivering proportional business value.
What you get
Sustainable Performance & Efficiency Playbook
Current performance reality, hosting costs, asset composition, and sustainability impact, framed as a business case. Includes scenario modelling across three optimisation levels and a "do nothing" projection.
Performance Baseline & Benchmark Scores
Lighthouse scores, Core Web Vitals, and page weight measurements across every tested page. Includes mobile vs desktop comparison and pattern analysis across templates, a repeatable baseline for measuring progress.
Cost & Carbon Impact Model
Scenario-based model estimating hosting cost savings, carbon reduction, and experience improvements across light optimisation, targeted structural work, and inaction. A concrete financial case grounded in your actual numbers.
Prioritised next-steps plan
Every finding mapped to a Now/Next/Later roadmap. Image optimisation and delivery tweaks separated from infrastructure changes. If you want to keep moving, the findings feed directly into a Spark roadmap.
Sustainable Performance & Efficiency Playbook
Current performance reality, hosting costs, asset composition, and sustainability impact, framed as a business case. Includes scenario modelling across three optimisation levels and a "do nothing" projection.
Performance Baseline & Benchmark Scores
Lighthouse scores, Core Web Vitals, and page weight measurements across every tested page. Includes mobile vs desktop comparison and pattern analysis across templates, a repeatable baseline for measuring progress.
Cost & Carbon Impact Model
Scenario-based model estimating hosting cost savings, carbon reduction, and experience improvements across light optimisation, targeted structural work, and inaction. A concrete financial case grounded in your actual numbers.
Prioritised next-steps plan
Every finding mapped to a Now/Next/Later roadmap. Image optimisation and delivery tweaks separated from infrastructure changes. If you want to keep moving, the findings feed directly into a Spark roadmap.
Sustainable Performance & Efficiency Playbook
Current performance reality, hosting costs, asset composition, and sustainability impact, framed as a business case. Includes scenario modelling across three optimisation levels and a "do nothing" projection.
Cost & Carbon Impact Model
Scenario-based model estimating hosting cost savings, carbon reduction, and experience improvements across light optimisation, targeted structural work, and inaction. A concrete financial case grounded in your actual numbers.
Performance Baseline & Benchmark Scores
Lighthouse scores, Core Web Vitals, and page weight measurements across every tested page. Includes mobile vs desktop comparison and pattern analysis across templates, a repeatable baseline for measuring progress.
Prioritised next-steps plan
Every finding mapped to a Now/Next/Later roadmap. Image optimisation and delivery tweaks separated from infrastructure changes. If you want to keep moving, the findings feed directly into a Spark roadmap.
FAQs about the audit.
FAQs about the audit.
Got questions? We’ve got answers. Here’s everything you need to know about our audit
Do we need to commit to optimisation work after a Cogworks performance audit?
No. A Cogworks Website Carbon and Performance Audit is a standalone deliverable. You receive the full playbook, baseline scores, cost model, and roadmap regardless of what happens next. Some clients take the quick-win list to their own developers. Others use the cost model to build the business case for a larger programme. The playbook gives you clarity and options; what you do with them is entirely your call.
Will a Cogworks performance audit tell us what to improve first?
Yes. Every finding in a Cogworks Website Carbon and Performance Audit is mapped to a recommended action and placed on a Now, Next, Later roadmap. The playbook separates light wins, image compression, delivery tweaks, from deeper structural work that requires template refactoring or infrastructure changes. Each action includes estimated impact on speed, cost, and sustainability, so your team can make informed trade-offs rather than guessing which improvements matter most.
How is a Cogworks performance audit different from running Lighthouse ourselves?
A Cogworks Website Carbon and Performance Audit goes significantly beyond what a single Lighthouse run can tell you. We test across representative page types to identify template-level patterns, then layer in hosting infrastructure review, real-world field data comparison, third-party script attribution, and carbon impact analysis. Critically, we build scenario models that quantify what each level of optimisation would save in hosting costs, load time, and carbon. The result is a strategic playbook your leadership team can act on, not a dashboard of scores.
Does a slow or heavy website actually cost more to run?
A Cogworks Website Carbon and Performance Audit frequently reveals that hosting costs are directly inflated by avoidable inefficiency. Unoptimised images, excessive third-party scripts, and poor caching force servers to work harder on every page view, and when traffic grows, those costs scale with it. Google research shows that as page load time rises from one to three seconds, the probability of a visitor leaving increases by 32%. The audit gives you a clear cost model showing exactly where spend is wasted and what different levels of optimisation would save.
How long does a website performance and sustainability audit take?
A Cogworks Website Carbon and Performance Audit typically takes two to three weeks from kickoff to final playbook. It begins with a short questionnaire and walkthrough to confirm the page set and hosting context. We then run Lighthouse testing, infrastructure review, third-party analysis, and field data validation. Most clients receive the complete playbook, including baseline scores, scenario models, and cost projections, within three weeks.
What happens next?
The Website Carbon and Performance Audit doesn't end with a report. Every finding connects to a recommended action and we'll walk you through what it would take to address each one. If you want to keep moving, the findings feed directly into a Spark roadmap so the work you've done here becomes the foundation for everything that comes next.
What can we help with?
Talk to a London digital consultancy and Umbraco Gold Partner
Whether it's a new build, a platform that needs looking after or a problem you haven't been able to get a straight answer on, tell us where you are and we'll take it from there.
Client Strategist
@ Cogworks
Katie Grant Watson
What can we help with?
Talk to a London digital consultancy and Umbraco Gold Partner
Whether it's a new build, a platform that needs looking after or a problem you haven't been able to get a straight answer on, tell us where you are and we'll take it from there.
Client Strategist
@ Cogworks
Katie Grant Watson
What can we help with?
Talk to a London digital consultancy and Umbraco Gold Partner
Whether it's a new build, a platform that needs looking after or a problem you haven't been able to get a straight answer on, tell us where you are and we'll take it from there.
Client Strategist
@ Cogworks
Katie Grant Watson