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 Paint10.0 s3.0 s< 2.5 s
First Input Delay800 ms150 ms< 100ms
Cumulative Layout Shift0.0870.034 0.1


Optimise images

By optimising the following images, roughly 394 KB could be removed from the transfer size, about 20%. This would reduce the CO2 generated per page load from 0.5g grams to 0.4 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.
chinese-fans.jpg 298 KB 15% 54 KB
burwood-north.png 251 KB 13% 7 KB

Replace jQuery and jQuery libraries with more modern code

jQuery is a popular and widely-used JavaScript library that simplifies web development by providing a set of tools and functions to interact with HTML documents, handle events, create animations, and make asynchronous HTTP requests.

In the past, jQuery was a very popular choice for web development because it simplified many common tasks and provided a consistent and cross-browser-compatible API. However, with the advancement of modern web technologies and improvements in browser capabilities, the need for jQuery has decreased.

Many modern web frameworks and libraries, such as React and Angular, provide their own set of tools for handling common tasks and interacting with the DOM, making jQuery less necessary in many cases. The Javascript engine in modern browsers have also become more consistent in the feature implementations often eliminating the need for a library like jQuery.

jQuery represents an opportunity because:

  1. Performance: While jQuery is a powerful and useful library, it can slow down website performance due to its large size and complex code. Modern browsers have also improved their native support for many of the features that jQuery provides, reducing the need for it.
  2. Maintainability: jQuery code can be difficult to maintain and update, particularly as web technologies evolve and change. This can make it harder for developers to keep up with best practices and standards for web development.
  3. Accessibility: Some jQuery plugins and features can create accessibility issues, particularly for users who rely on assistive technologies. This can make it harder for people with disabilities to use and access websites.
jquery.min.js 34 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.
Timing3.6 s1.0 s

Largest Contentful Paint

Timing10.0 s3.0 s

Total Blocking Time

Timing970 ms110 ms

Cumulative Layout Shift


Speed Index

Timing8.6 s3.7 s

Time to Interactive

Timing12.1 s2.8 s

Max Potential First Input Delay

Timing800 ms150 ms

First Meaningful Paint

Timing3.6 s1.0 s

Eliminate render-blocking resources

InsightPotential savings of 940 msPotential savings of 170 ms

Properly size images

InsightPotential savings of 157 KiBPotential savings of 194 KiB

Defer offscreen images

InsightPotential savings of 601 KiBPotential savings of 304 KiB

Reduce unused CSS

InsightPotential savings of 91 KiBPotential savings of 38 KiB

Reduce unused JavaScript

InsightPotential savings of 238 KiBPotential savings of 239 KiB

Efficiently encode images

InsightPotential savings of 136 KiBPotential savings of 95 KiB

Serve images in next-gen formats

InsightPotential savings of 826 KiBPotential savings of 698 KiB

Reduce initial server response time

InsightRoot document took 1,380 msRoot document took 960 ms

Avoid multiple page redirects

InsightPotential savings of 1,110 msPotential savings of 340 ms

Avoids enormous network payloads

InsightTotal size was 1,996 KiBTotal size was 1,931 KiB

Serve static assets with an efficient cache policy

Insight16 resources found16 resources found

Avoid an excessive DOM size

Insight1,059 elements1,050 elements

JavaScript execution time

Timing3.3 s0.8 s

Minimizes main-thread work

Timing5.1 s1.5 s

All text remains visible during webfont loads


Uses passive listeners to improve scrolling performance


Image elements do not have explicit width and height