Advanced PageSpeed scan technical overview
An Advanced scan is an in-depth scan and includes issues that require full admin access to the server.
This means that for many shared hosting accounts the required access to make these changes will not be provided. A Virtual Private Server (VPS) with SSH access is generally required. In some instances the host may make requested changes on your behalf, if it is permitted withing their operating guidelines.
We would recommend moving to a VPS if ultimate performance is sought and can help with this if required.
Please note that the metrics we provide relating to performance on WPScanly are calculated from the Standard scan, and so are more in line with sites providing performance metrics.
Compared to a Standard scan, the Advanced scan provides lab data and other metrics that give additional information to improve the performance of the site. Both Standard and Advanced scans use Googles PageSpeed Insight Lighthouse to generate a performance score that estimates the page’s performance.
Below we introduce the topics covered by the Advanced scan and link to further reading if you would like more indepth details.
Lab data generates a performance score that estimates the page’s performance on different metrics.
- First Contentful Paint
- Largest Contentful Paint
- Speed Index
- Time to Interactive
- Total Blocking Time
- Cumulative Layout Shift
First Contentful Paint (FCP)
This metric measures the time from when the page starts loading to when any part of the page’s content is rendered on the screen. For this metric, “content” refers to text, images (including background images), <svg> elements, or non-white <canvas> elements. More info here
Largest Contentful Paint (LCP)
This metric reports the render time of the largest content element visible within the viewport. More info here
This metric measures how quickly content is visually displayed during page load. Lighthouse first captures a video of the page loading in the browser and computes the visual progression between frames.
More info here
Time to Interactive
This metric measures how long it takes a page to become fully interactive. A page is considered fully interactive when:
· The page displays useful content, which is measured by the First Contentful Paint,
· Event handlers are registered for most visible page elements, and
· The page responds to user interactions within 50 milliseconds.
More info here
Total Blocking Time
This metric measures the total amount of time between First Contentful Paint (FCP) and Time to Interactive (TTI) where the main thread was blocked for long enough to prevent input responsiveness.
More info here
Cumulative Layout Shift
This metric measures the sum total of all individual layout shift scores for every unexpected layout shift that occurs during the entire lifespan of the page. More info here