Insights

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
33%
Desktop Performance
66%

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.

VitalMobileDesktopTarget
Largest Contentful Paint12.6 s2.8 s< 2.5 s
First Input Delay1,020 ms360 ms< 100ms
Cumulative Layout Shift0.0380.022 0.1

Opportunities

Optimise images

By optimising the following images, roughly 274 KB could be removed from the transfer size, about 11%. This would reduce the CO2 generated per page load from 0.63g grams to 0.56 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.
breakout50_xl.png 391 KB 16% 146 KB
figure_col12_lg.jpg 246 KB 10% 2 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.

NetworkSans-2019-Bold.woff ~40 KB ~23 KB
NetworkSans-2019-Regular.woff ~39 KB ~22 KB

Convert font files to woff2

WOFF2 is considered to be the best font format for web use because it provides a good balance of file size and compatibility. Some specific reasons why WOFF2 is a good font format include:

  1. Small file size: WOFF2 is a compressed font format, which means that it has a smaller file size compared to other font formats like TTF or OTF. This is important for web use because smaller file sizes can help to reduce the amount of data that needs to be downloaded, leading to faster page load times.
  2. High-quality font rendering: WOFF2 provides high-quality font rendering, making it a good choice for use on the web.

It’s worth noting that WOFF2 is not the only font format that can be used on the web, and there may be cases where other formats like WOFF or TTF are more suitable, depending on the specific requirements of the website. However, for most cases, WOFF2 is considered to be the best font format for web use due to its combination of small file size, good browser support, and high-quality font rendering.

Fontformat
NetworkSans-2019-Bold.woffwoff
NetworkSans-2019-Regular.woffwoff

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.
MobileDesktop
Score0%35%
Timing8.4 s1.9 s

Largest Contentful Paint

MobileDesktop
Score0%39%
Timing12.6 s2.8 s

Total Blocking Time

MobileDesktop
Score23%78%
Timing1,120 ms210 ms

Speed Index

MobileDesktop
Score13%46%
Timing9.2 s2.4 s

Time to Interactive

MobileDesktop
Score16%89%
Timing12.1 s2.5 s

Max Potential First Input Delay

MobileDesktop
Score0%24%
Timing1,020 ms360 ms

First Meaningful Paint

MobileDesktop
Score3%30%
Timing8.7 s2.0 s

Eliminate render-blocking resources

MobileDesktop
Score10%48%
InsightPotential savings of 4,120 msPotential savings of 940 ms

Properly size images

MobileDesktop
Score58%100%
InsightPotential savings of 123 KiB

Reduce unused CSS

MobileDesktop
Score67%90%
InsightPotential savings of 73 KiBPotential savings of 64 KiB

Reduce unused JavaScript

MobileDesktop
Score10%48%
InsightPotential savings of 682 KiBPotential savings of 680 KiB

Serve images in next-gen formats

MobileDesktop
Score41%71%
InsightPotential savings of 285 KiBPotential savings of 579 KiB

Initial server response time was short

MobileDesktop
GradeFailPass
InsightRoot document took 770 msRoot document took 600 ms

Avoid serving legacy JavaScript to modern browsers

MobileDesktop
Score88%97%
InsightPotential savings of 33 KiBPotential savings of 33 KiB

Avoids enormous network payloads

MobileDesktop
Score98%94%
InsightTotal size was 2,066 KiBTotal size was 2,435 KiB

Serve static assets with an efficient cache policy

MobileDesktop
Score21%19%
Insight24 resources found26 resources found

JavaScript execution time

MobileDesktop
Score75%97%
Timing2.1 s0.8 s

Minimizes main-thread work

MobileDesktop
Score61%97%
Timing3.4 s1.4 s

Ensure text remains visible during webfont load

MobileDesktop
GradeFailFail

Minimize third-party usage

MobileDesktop
GradeFailPass
InsightThird-party code blocked the main thread for 420 msThird-party code blocked the main thread for 80 ms

Image elements do not have explicit width and height

MobileDesktop
GradeFailFail