Pagespeed Insights (PSI): Turbo for your website

This is what you can expect in our detailed article about PageSpeed Insights 😉
What is Google PageSpeed Insights?
Why is PageSpeed Insights used for?
What metrics does PageSpeed Insights measure?
How can you use PageSpeed Insights for your business?
Advantages and disadvantages of PSI
What is the difference between lab and field data?
General recommendations and tips
Common tools for improving PageSpeed
FAQs

What is Google PageSpeed Insights?

Google PageSpeed Insights (PSI) is a free tool from Google that analyses and evaluates the performance of your website. It has been continuously developed and improved since its first launch in 2011. It measures the loading speed and behaviour of your site on both mobile devices and desktops and provides concrete suggestions for improvement. PSI combines field data from the Chrome User Experience Report (CrUX) and lab data generated by automated tests with Lighthouse.
In addition, the page structure is analysed with regard to accessibility, best practices and SEO .
In addition to the Pagespeed Online tool, there is also a public Pagespeed Insights API that can be used in your own tools / plugins.

Why do companies use PageSpeed Insights?

Companies and webmasters use the tool to check the loading times of their websites and identify optimisation potential. A fast PageSpeed score can improve the user experience, reduce the bounce rate and increase the conversion rate. In addition, factors such as loading speed, accessibility or the structure of a website also influence the ranking in search engine results.

Which metrics does PageSpeed Insights measure?

In addition to the core web vitals Largest Contentful Paint (LCP), Interaction To Next Paint (INP) and Cumulative Layout Shift (CLS), other important metrics such as First Contentful Paint (FCP), Time To First Byte (TTFB), First Input Delay (FID), Speed Index (SI) or Total Blocking Time (TBT) are also used to evaluate performance.

How can you use PageSpeed Insights for your company?

1. analyse your website

Enter the URL of your website in PageSpeed Insights to get an overview of the current performance.

The analysis provides a score between 0 and 100.
A value between 90 and 100 is rated as fast, between 50 and 89 as average and below 50 as slow.

2. identification of weak points

PageSpeed Insights reports highlight specific areas that can be improved. Typical weaknesses include:
Performance

• Non-optimised images
• Lack of lazy loading
• Unnecessary JavaScript and CSS resources
• Lack of caching strategy
• Render blocking resources

Accessibility

• Lack of contrast
• Alt tags in images
• Missing labelling of buttons
• Too small size of buttons or links
• Missing screen reader labelling (Aria states and properties)

Best practices

• Use of outdated APIs / third-party cookies
• Debugging/error messages in the console

SEO

• Links incorrectly labelled with nofollow
• Incomplete metadata (e.g. meta description, canonical tag, title tag, structured data)
• Missing or incorrect robots.txt

The specific weightings of the performance metrics are not visible in the Lighthouse report itself, but can be simulated in the “Lighthouse Scoring Calculator“. You can use this tool to calculate the PageSpeed score based on your own data.

3. implementation of optimisations

Depending on the CMS/system, some improvements can be realised via plugins or extensions (system-dependent). Some must or can be implemented on the server or code side.
WordPress, for example, offers numerous plugins for caching or image optimisation, whereas a server response time or unnecessary CSS / JS should be changed with human intelligence in the server configuration or the code.

Whether and with what effort these suggestions can be implemented depends primarily on the system used.

4. check the improvements

Check the effect of your optimisation measures and focus on the lab data, as changes in the field data do not have an immediate effect.
If technically feasible, optimisation measures should be tried out in a test system before publication.

5 Continuous monitoring

After implementing the optimisations, you should regularly monitor the performance of your website to ensure that the improvements are sustainable. Continuous monitoring also helps to recognise and rectify new weak points at an early stage, e.g. when new pages are added, pages are changed, new libraries are used, etc.

Advantages and disadvantages of PSI

Advantages

• Free of charge: PageSpeed Insights is a free tool that is accessible to everyone.
• User-friendly: The tool is easy to use and provides clear reports and recommendations.
• Detailed analyses: PSI provides detailed insights into various performance metrics and gives specific suggestions for improvement.
• Improved SEO: Optimisations based on PSI reports can improve SEO rankings.

Disadvantages

• Limited historical data: PSI only shows current analyses and no historical performance data.
• Dependence on lab data: Lab data does not always reflect the actual user experience.
• Fluctuating results: Results may vary depending on the timing of the analysis and external factors.

What is the difference between lab and field data?

• Lab data: Laboratory data is collected in a controlled environment with defined parameters. It is based on automated tests performed with tools such as Lighthouse. These tests simulate user interactions under optimal conditions to provide consistent and reproducible results. Lab data is useful for analysing technical aspects of page performance and identifying specific optimisation potential.
• Field data: Field data is collected from the real use of the website by real users. It comes from the Chrome User Experience Report (CrUX) and reflects the actual loading times and interactions of users in different environments and networks. Field data provides insights into the real user experience and can be influenced by factors such as different devices, networks and locations.
• To summarise: Lab data provides controlled, technical analyses, while field data reflects the real user experience. Both types of data are important to get a comprehensive picture of website performance and make targeted optimisations.

General recommendations and tips

1. Optimise images: Use compressed and correctly formatted images (WEBP, AVIF, SVG). In most cases, you can achieve better results with these image formats than with JPG, PNG or GIF. Create sufficient image derivatives to serve the different screen resolutions with the appropriate image sizes.
2. Font optimisation: Avoid loading large font files and implement font display options to reduce loading times. Provide fonts on your own server.
3. Content Delivery Network (CDN): Use a CDN to deliver content faster to users worldwide.
4. Server optimisation: Improve server response time with high-performance hosting services and server-side optimisations.
5. Use plugins / extensions sparingly: Many of the problems shown can be solved with plugins. For example, completely equipping an existing website with new images (e.g. WEBP) can be very time-consuming without a CDN. Use a plugin that automatically converts and displays the old data and ensure that the new files are in the correct format. Bear in mind that every additional plugin takes up resources and the cost-benefit factor should be critically scrutinised.
6. Use Search Console: Also use the Google Search Console to recognise problems with individual pages more quickly.
7. Check system updates: Test and assess technical changes to the website before publishing to avoid unpleasant surprises.
8. Regular review: Carry out regular PSI analyses to continuously identify and implement improvements.

You can find a more detailed description of performance, structure, etc. at https://web.dev/learn/

Common tools for improving page speed

FAQs

1. What is the PageSpeed score?

The PageSpeed score is a rating scale from 0 to 100 that evaluates the performance of a website based on various metrics. A higher score indicates better performance.

2. Why are PageSpeed Insights important for SEO?

PageSpeed Insights are important for SEO because the loading speed of a website is a ranking factor for Google. Faster websites offer a better user experience and can lead to higher rankings in the search results. In addition, topics such as accessibility and structural SEO are becoming increasingly important.

3. How often should I check my website with PageSpeed Insights?

It is recommended to check the website regularly, ideally monthly, with PageSpeed Insights to ensure that performance is continuously optimised. It is also advisable to check after technical changes.

4. What can I do if my website has a low score?

If your website has a low score, you should implement the optimisations suggested by PageSpeed Insights, such as image optimisation, code minimisation and implementation of caching strategies.

5. Do external resources affect my PageSpeed Insights score?

Yes, external resources such as third-party scripts and embedded content can affect load times and therefore impact the PageSpeed Insights score. Optimise or remove these resources to improve performance.

6. What are the Core Web Vitals?

The Core Web Vitals are specific metrics that Google classifies as critical to the user experience. These include LCP, INP (formerly First Input Delay FID) and CLS.

7. Can I improve the performance of my website without technical knowledge?

Yes, many of the optimisations suggested by PageSpeed Insights do not require deep technical knowledge and can be implemented using plugins or simple tweaks.