Google Lighthouse Performance

The Google Lighthouse performance score is a metric that measures the speed and performance of a website. It’s an overall score that ranges from 0 to 100 and is generated based on a number of different performance metrics, such as the time it takes for a website to load, the time it takes for a website to become interactive, the size of the resources used by the website, and other factors that impact the user experience.

A high performance score in Google Lighthouse indicates that a website is fast and responsive, which can lead to a better user experience and improved search engine rankings. On the other hand, a low performance score can indicate that a website is slow and unresponsive, and can negatively impact the user experience.

Mobile Performance
Desktop Performance

Core Web Vitals

Core Web Vitals are a set of specific factors that Google considers important in a webpage’s overall user experience. Core Web Vitals are made up of three specific page speed and user interaction measurements: Largest Contentful PaintFirst Input Delay, and Cumulative Layout Shift.

Largest Contentful Paint11.3 s2.2 s< 2.5 s
First Input Delay950 ms220 ms< 100ms
Cumulative Layout Shift0.0450.03 0.1

Tracking scripts

All the tracking scripts on the site generated ~159 KB of data

A tracking script is a code snippet designed to track the flow of visitors who visit a website. Media, advertising, and analytics organisations will provide a script to add to your website that sends data directly to their servers. This data can then be used to measure goals and conversions, analyse user behaviour, and influence advertising campaigns.

Consider how much of this data you actually need and use? How often do you review the analytics data, and does this inform genuine change? Are you actively running social media campaigns? Consider pausing or removing tracking scripts that aren’t being actively used. 2 139 KB 3 20 KB 2 574 B 1 0 B


Optimise images

By optimising the following images, roughly 623 KB could be removed from the transfer size, about 35%. This would reduce the CO2 generated per page load from 0.47g grams to 0.3 grams.

Images should be optimised for the web for several reasons:

  1. Reduced file size: Optimizing images can result in a smaller file size, which can help to reduce the amount of data that needs to be downloaded. This can lead to faster page load times and improved performance.
  2. Improved user experience: Optimising images can help to improve the overall user experience, as pages with optimised images load faster and are more responsive.
  3. Lower emissions: Optimising images can help to reduce the emissions associated with data transfer, as less data needs to be transmitted over the network.
  4. Better accessibility: Optimising images can make them more accessible to users with slower connections or limited data plans.
VAEA1853-Website-Banners-FA1-Front.jpg 536 KB 30% 428 KB
Icon%20VAEAs%20Work.jpg 99 KB 5% 82 KB
Icon%20Asbestos.jpg 61 KB 3% 51 KB
Icon%20Structure.jpg 45 KB 3% 38 KB
vaea-logo-footer.png 24 KB 1% 14 KB
vaea-logo-header.png 20 KB 1% 11 KB

Subset large font files

Fonts should be subsetted to reduce the file size, improve performance, and reduce emissions. Subsetting a font involves removing any characters that are not needed for a particular use case, resulting in a smaller file size and faster page load times. Some specific reasons why fonts should be subsetted include:

  1. Reduced file size: Subsetting a font removes any unused characters, which can result in a smaller file size. This can help to reduce the amount of data that needs to be downloaded, leading to faster page load times and lower emissions.
  2. Improved performance: Fonts that are subsetted are faster to load and render than fonts that are not subsetted. This can help to improve the overall performance of a website, leading to a better user experience.

Overall, subsetting fonts is a good practice for anyone looking to optimize the performance and reduce the emissions of a website of a website.

VIC-Medium.7792938.woff2 ~24 KB ~6 KB
VIC-Bold.6690f57.woff2 ~24 KB ~6 KB
VIC-Regular.0d446b7.woff2 ~23 KB ~6 KB
VIC-SemiBold.0a0482a.woff2 ~22 KB ~5 KB

Largest Contentful Paint

Timing11.3 s2.2 s

Total Blocking Time

Timing740 ms90 ms

Cumulative Layout Shift


Speed Index

Timing8.5 s2.3 s

Time to Interactive

Timing9.7 s1.8 s

Max Potential First Input Delay

Timing950 ms220 ms

Properly size images

InsightPotential savings of 538 KiBPotential savings of 681 KiB

Reduce unused JavaScript

InsightPotential savings of 264 KiBPotential savings of 263 KiB

Efficiently encode images

InsightPotential savings of 316 KiBPotential savings of 381 KiB

Serve images in next-gen formats

InsightPotential savings of 541 KiBPotential savings of 623 KiB

Reduce initial server response time

InsightRoot document took 950 msRoot document took 1,120 ms

Avoids enormous network payloads

InsightTotal size was 1,717 KiBTotal size was 1,805 KiB

Serve static assets with an efficient cache policy

Insight15 resources found15 resources found

JavaScript execution time

Timing2.1 s0.4 s

Minimizes main-thread work

Timing3.1 s0.7 s

Image elements do not have explicit width and height