What is Lighthouse

Lighthouse is Google’s automated auditing tool that assesses the quality of a web page. Audits can be run against a web page (mobile or desktop) and covers five key areas:

• Performance
• Accessibility
• Best Practices
• Search Engine Optimization (SEO)
• Progressive Web Apps (PWA)

Each area tested receives a score out of 100, the results also provide details where each metric could be improved.

An audit is a singular one-off report, which makes it a challenge to benchmark results over time and is therefore a limiting factor when looking to measure for improvement or regression.

Webspeed Index addresses this by collecting and charting all Lighthouse reports ran against a web page over time. This provides an invaluable insight to measure uplift or regression.

It is also possible to view your Lighthouse score in comparison to your competitors which can highlight opportunities to gain a competitive advantage and become more favourable with Google indexes.

What do each of the Categories Measure?

Performance

The Performance category checks the web performance characteristics of your website focusing on key metrics that Google considers important for page ranking and user experience.

Why Does the Performance Score Matter?

Google want to direct their users to a web page that not only delivers good content but loads fast so that a good experience is delivered overall.

To enforce this approach Google have announced a set of user experience metrics called Web Vitals and they are to be included within their ranking algorithms from May 1st 2021.

The metrics focus specifically on the user experience and are of key importance as they comprise 55% of the Lighthouse performance score.

Accessibility

This category checks for and highlights opportunities to improve the user accessibility of your website.

Why Does the Accessibility Score Matter?

If your website isn’t accessible to its visitors, then it may be penalised in this area of customer experience which is a facet measured by search engine ranking algorithms. Consequently, your website may struggle to be indexable by search engines that implement this level of assessment.

Best Practices

Best Practices audits review the coding techniques and technology implementation of your website and verifies it against industry accepted best practice.

Why Does the Best Practice Score Matter?

Two of the most important checks here are for deprecated technologies and security. Ensuring that deprecated technologies are not used in the website means that your website is should work more consistently across regularly updating browsers. This enables you to future proof against increased costs that are associated with improving or upgrading your website code.

Security is important as it builds trust for an online users, Google will warn users if they land on or navigate to a page that is not HTTP protected. Additionally, websites that have forms or accept online payments require strong security measures to be in place as this is a key element of securing a conversion.

SEO

The SEO category audits to ensure that your web page is optimized for search engine results ranking.

Why Does the SEO Score Matter?

The more optimised your page is for SEO the higher the potential that your website will atract high scoring ranking factors that determine how web pages will appear in a SERP (search engine results page). Consequently, this can directly impact the volume of traffic a website will receive.

PWA

If your website is a progressive web app, this set of audits validates it against the technical requirements required to perform as a PWA. A PWA is a specific Google-inspired design approach for implementing a website and may not apply to all websites.

Why Does the PWA Matter?

Unless you need your website to behave as a PWA this metric is probably not important to you. However, for PWA's, these audits ensure that the design principles have been implemented and also provides guidelines that can limit any App store inhibitors or restrictions.

Summary

Lighthouse audits are a great way to take a snapshot of web page performance, however unless you are able to benchmark overtime it is impossible to measure how change has impacted on your web performance and user experience.

Reaching 100 on all Lighthouse metrics does not mean you have the best web page, it is just an indication to Google that the page conforms to their best practice requirements.

For a full view of page performance and user experience Webspeed Index can provide a holistic view, contact us now to discuss.