Lighthouse is a tool created by Google and was originally meant to audit Progressive Web Apps (PWA). In general, this tool will do four audits for accessibility, performance, progressive web apps and an extended list of best practices. With a flaky 3G connection on a slightly underpowered device, Google Lighthouse stimulates your mobile site visitors. The main purpose of Google Lighthouse is to increase a site speed through measuring page speed from a different, more realistic angle. This surely makes Lighthouse very recommended to any web developers and SEO services who aims for a faster loading Mobile site speed. However, some people are more familiar with PageSpeed instead of Google Lighthouse, so what’s the difference between Page Speed Insights and Google Lighthouse?
PageSpeed Insights vs.Google Lighthouse
Right now, PageSpeed Insights is still the most popular analysis tool which can provide you with a nice score and a list of possible improvements. However, it hardly gives you an idea of the perceived loading speed of your site. Moreover, it also states that your site doesn’t follow the rules and therefore, it is slow for everyone. Here are the two most important things PageSpeed Insights looks at:
- Time to above-the-fold load: This is the time that it takes to fully render the above-the-fold content of a page from the moment a user requests your page.
- Time to full page load: This is the time that it takes to fully render the complete content of a page from the moment a user requests your page.
On the other hand, Lighthouse focuses on practical approach where it puts user experience front and center. Since it visits your site over a throttled 3G connection, it can predict what a real visitor would experience. Moreover, Lighthouse will check how and when it responds to input while PageSpeed Insights will just load your site. No wonder Lighthouse can easily find the exact moment when your content is ready to use.
What to Look for in Lighthouse Results?
The important point that users want to see and feel is that your site must be fast and must feel fast. In other words, users should be able to interact with your content as soon as possible. This is absolutely important for your SEO; therefore, you need to fix these issues. There are several metrics that Lighthouse uses such as follows:
- First meaningful paint: This metric will determine how long content should appear on screen. The lower the score, the faster the page appears.
- First interactive: it will also measure if a page is minimally interactive.
- Consistently interactive: This measures when a page is fully interactive.
- Perceptual Speed Index: This shows how quickly the contents of a page are visibly populated which also comes with a target loading time of <1,250 ms.
- Estimated latency input: This measures how long your page will respond to user input.
- Critical requests chain: It shows what resources are needed to initially render this page.
Even though Lighthouse is not as popular as PageSpeed, its functionality cannot be ignored. In fact, this is a worth to try tool for those who want to analyze their site speed. In fact, it is more fine-grained and gives you immediate feedback based on real-world usage.