A new type of check is now available for all users. We're calling it a "Quality check" because it measures four of the most important quality indicators for a website: Performance, Best Practices, SEO, and Accessibility.

"But wait", you say. "These four indicators sound very familiar..."

And yes, this is in fact a Lighthouse check 

We decided to name it "Quality check" since not everybody is familiar with Lighthouse, and we feel this name is more telling. 

Well, now that we got this out of the way, let's look at what it can do.

Unlike a traditional Lighthouse check, this check helps you automate your website monitoring. 

It runs once a day and helps you keep track of the quality of your pages. You can get notified if the score drops below a certain threshold. 

You also get the freedom to choose if the check should emulate a mobile- or a desktop device.

Now let's look at the metrics we capture 👇

Metrics*

Performance: Audits for metrics like first paint and time to interactive to determine lag.

Best Practices: Looks for everything from HTTPS usage to correct image aspect ratios.

SEO: Checks for best practices to ensure your site is discoverable.

Accessibility: Checks for common issues that may prevent users from accessing your content.

Web vitals (part of performance)

• First Contentful Paint marks the time at which the first text or image is painted.
• Speed Index shows how quickly the contents of a page are visibly populated.
• Largest Contentful Paint marks the time at which the largest text or image is painted.
• Time to interactive is the amount of time it takes for the page to become fully interactive. 
• Total Blocking Time is the sum of all time periods between FCP and Time to Interactive, when task length exceeded 50ms, expressed in milliseconds.
• Cumulative Layout Shift measures the movement of visible elements within the viewport. 

*Description borrowed from Web.dev.

One of the very valuable things Lighthouse brings is its reports. These include diagnostics and opportunities sections which help you improve your site's overall quality. 

You can access these reports by clicking the "View latest report"-button or by clicking on one of the log entries.