This approximates when the main content of the page is visible to the users. 

The elements that are taken into consideration for Largest Contentful Paint: 

• <img> elements
• <image> elements inside an ...

Causes: 

• Slow server response times
• Render-blocking JavaScript and CSS
• Resource load times
• Client-side rendering

For improvements, some relevant techniques:

While anything you do to improve page load speed will improve your Speed Index score, addressing the following should have a particularly big impact:

        Name - Weight in score - Summary

1. First Contentful Paint (FCP) - 10% - Time to paint the first text or image
2. Time to Interactive (TTI) - 10% - Necessary time for the app to become fully interactive (responding within 50ms from user interaction)
3. Speed Index (SI)...

TBT measures the total amount of time that a page is blocked from responding to user input, such as mouse clicks, screen taps, or keyboard presses. The sum is calculated by adding the blocking portion of all 

It 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  
• Event handlers are registered for most visible page elements,...

CLS is a measure of the largest burst of layout shift scores for every 

How to improve:

• Always inclu...

Try to diagnose the root cause of long tasks, using 

In general, the most common causes are:

 Some of the values are calculated based on 

If you don't have a very specific reason to optimise only one of the metrics, the be...

PRPL is an acronym that describes a pattern used to make web pages load and become interactive, faster:

• Push (or preload) the most important resources.
• Render the initial route as soon as possible.
• Pre-cache