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 Paint2.7 s0.7 s< 2.5 s
First Input Delay120 ms30 ms< 100ms
Cumulative Layout Shift0.0230.061 0.1

Tracking scripts

All the tracking scripts on the site generated ~69 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. 1 748 B 1 48 KB 2 21 KB 1 573 B


Remove autoplaying or preloaded media files

By removing 2 autoplaying or preloaded videos, roughly 1.5 MB could be removed from the page load.

This would reduce the page transfer size by 38% and reduce the pages emissions from 1.02 grams of CO2 to 0.64 grams of CO2.

Autoplaying videos can have a negative impact on the user experience for several reasons:

  1. Increased data usage: Autoplaying videos can consume a lot of data, especially if they are set to play in high definition. This can be a problem for users with limited data plans or slow connections, who may experience slow or interrupted playback.
  2. Annoyance factor: Autoplaying videos can be annoying for users, especially if they are accompanied by sound. This can lead to a negative perception of the website and decreased engagement.
  3. Reduced accessibility: Autoplaying videos can be a problem for users with accessibility needs, such as users who are blind or have hearing difficulties.
  4. Increased page load time: Autoplaying videos can increase the overall page load time, leading to a slower user experience.
  5. Decreased battery life: Autoplaying videos can consume a lot of battery power, especially on mobile devices, leading to reduced battery life.

In order to minimise the impact of autoplaying videos on the user experience, it is recommended to use them sparingly and only when necessary. It is also important to provide users with the option to turn off autoplaying videos and to allow them to control the playback of videos on the page. Additionally, videos should be optimised for performance and should be accompanied by captions or transcripts to improve accessibility.

Orora_Banner_5.mp4 936 KB 24%
Orora_Banner_5.webm 559 KB 14%

Optimise images

By optimising the following images, roughly 2 MB could be removed from the transfer size, about 40%. This would reduce the CO2 generated per page load from 1.02g grams to 0.61 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.
featured-home-content-block.png 563 KB 14% 501 KB
home-content-block-3.png 448 KB 11% 403 KB
home-content-block-1.png 388 KB 10% 362 KB
home-content-block-2.png 293 KB 7% 267 KB
ORORA_CTA_Banner.jpeg 77 KB 2% 31 KB
WILO.jpeg 41 KB 1% 18 KB
Closed_Loop_Process_-_Header_Image.jpeg 26 KB 1% 11 KB
Website_Image_News_2.png 11 KB 0% 8 KB

Replace icon font files

Font icons can have a negative impact on performance and emissions because they can increase the size of the page and the amount of data that needs to be downloaded. Some specific reasons why font icons can be bad for performance and emissions include:

  1. Increased file size: Font icons are typically included as part of a web font, which can be a large file that needs to be downloaded. This can increase the overall size of the page, leading to slower load times and higher emissions.
  2. Inefficient rendering: Web fonts are sometimes loaded and rendered inefficiently, which can result in slow performance and higher emissions.
  3. Unused icons: Font icons often include a large number of icons that may not be used on a particular page, increasing the file size and leading to inefficient use of resources.

While icon fonts are still widely used on the web, and they can be a useful tool for adding icons to a website. it is a dated practice when there are better options such as SVG icons, which can be more efficient and have a lower impact on performance and emissions.

icomoon.ttf5 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.

font.woff2 ~128 KB ~110 KB
324362_1_0.woff2 ~59 KB ~41 KB
324362_0_0.woff2 ~58 KB ~41 KB

First Contentful Paint

First Contentful Paint (FCP) is a performance metric that measures the time it takes for the first piece of content to be rendered on the screen when a user navigates to a web page. This content can be any visual element on the page, such as text, images, or a background color.

FCP is important because it directly affects the perceived speed of a website, and can impact user engagement and conversion rates. A faster FCP can lead to a better user experience and improved performance.

Here are a few ways you can optimise your FCP:

  1. Optimise images: Large, unoptimised images can slow down a page’s FCP. You can optimise images by compressing them, reducing their dimensions, and choosing the right format for each image.
  2. Minimise HTTP requests: Each resource requested by a web page, such as images, scripts, and stylesheets, requires a separate HTTP request. Minimising the number of HTTP requests can help to reduce the time it takes for a page to render.
  3. Prioritize critical content: Prioritizing critical content, such as above-the-fold content, can help to ensure that users see something on the screen quickly, even if the rest of the page is still loading.
  4. Reduce server response time: A slow server response time can significantly impact FCP. Optimizing server-side code and server settings can help to reduce response times and improve FCP.
  5. Use a performance monitoring tool: There are many tools available that can help you monitor your website’s performance, including FCP. These tools can help you identify performance issues and track your progress as you implement optimizations.
Timing2.4 s0.6 s

Largest Contentful Paint

Timing2.7 s0.7 s

Total Blocking Time

Timing150 ms0 ms

Cumulative Layout Shift


Speed Index

Timing4.5 s1.7 s

Time to Interactive

Timing4.7 s0.6 s

Max Potential First Input Delay

Timing120 ms30 ms

First Meaningful Paint

Timing2.4 s0.6 s

Eliminate render-blocking resources

InsightPotential savings of 590 msPotential savings of 60 ms

Properly size images

InsightPotential savings of 32 KiBPotential savings of 57 KiB

Reduce unused CSS

InsightPotential savings of 22 KiBPotential savings of 16 KiB

Reduce unused JavaScript

InsightPotential savings of 124 KiBPotential savings of 123 KiB

Serve images in next-gen formats

InsightPotential savings of 1,601 KiBPotential savings of 1,601 KiB

Reduce initial server response time

InsightRoot document took 870 msRoot document took 1,240 ms

Avoid enormous network payloads

InsightTotal size was 3,959 KiBTotal size was 3,962 KiB

Serve static assets with an efficient cache policy

Insight22 resources found22 resources found

JavaScript execution time

Timing0.7 s0.1 s

Minimizes main-thread work

Timing2.3 s0.5 s

Ensure text remains visible during webfont load


Image elements do not have explicit width and height