A large DOM will increase memory usage, cause longer [style calculations](https://developers.google.com/web/fundamentals/performance/rendering/reduce-the-scope-and-complexity-of-style-calculations), and produce costly [layout reflows](https://developers.google.com/speed/articles/reflow)

This is the largest contentful element painted within the viewport

Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this

Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles

Speed Index shows how quickly the contents of a page are visibly populated

The Critical Request Chains below show you what resources are loaded with a high priority. Consider reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load

First Meaningful Paint measures when the primary content of a page is visible

Server latencies can impact web performance. If the server latency of an origin is high, it's an indication the server is overloaded or has poor backend performance

Cumulative Layout Shift measures the movement of visible elements within the viewport

First Contentful Paint marks the time at which the first text or image is painted

Text-based resources should be served with compression (gzip, deflate or brotli) to minimize total network bytes

Sum of all time periods between FCP and Time to Interactive, when task length exceeded 50ms, expressed in milliseconds

Image formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption

Service worker is the technology that enables your app to use many Progressive Web App features, such as offline, add to homescreen, and push notifications. With proper service worker and manifest implementations, browsers can proactively prompt users to add your app to their homescreen, which can lead to higher engagement

Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this

Optimized images load faster and consume less cellular data

Large network payloads cost users real money and are highly correlated with long load times

Keep the server response time for the main document short because all other requests depend on it

Largest Contentful Paint marks the time at which the largest text or image is painted

These DOM elements contribute most to the CLS of the page

A long cache lifetime can speed up repeat visits to your page

The maximum potential First Input Delay that your users could experience is the duration of the longest task

If the LCP element is dynamically added to the page, you should preload the image in order to improve LCP

Third-party code can significantly impact load performance. Limit the number of redundant third-party providers and try to load third-party code after your page has primarily finished loading

Network round trip times (RTT) have a large impact on performance. If the RTT to an origin is high, it's an indication that servers closer to the user could improve performance

To set budgets for the quantity and size of page resources, add a budget.json file

Time to Interactive is the amount of time it takes for the page to become fully interactive

These DOM elements contribute most to the CLS of the page

Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles

Optimized images load faster and consume less cellular data

Lists the longest tasks on the main thread, useful for identifying worst contributors to input delay

The maximum potential First Input Delay that your users could experience is the duration of the longest task

Image formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption

Speed Index shows how quickly the contents of a page are visibly populated

This is the largest contentful element painted within the viewport

Text-based resources should be served with compression (gzip, deflate or brotli) to minimize total network bytes

Large network payloads cost users real money and are highly correlated with long load times

Time to Interactive is the amount of time it takes for the page to become fully interactive

Third-party code can significantly impact load performance. Limit the number of redundant third-party providers and try to load third-party code after your page has primarily finished loading

Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this

First Meaningful Paint measures when the primary content of a page is visible

Network round trip times (RTT) have a large impact on performance. If the RTT to an origin is high, it's an indication that servers closer to the user could improve performance

Cumulative Layout Shift measures the movement of visible elements within the viewport

A large DOM will increase memory usage, cause longer [style calculations](https://developers.google.com/web/fundamentals/performance/rendering/reduce-the-scope-and-complexity-of-style-calculations), and produce costly [layout reflows](https://developers.google.com/speed/articles/reflow)

A long cache lifetime can speed up repeat visits to your page

To set budgets for the quantity and size of page resources, add a budget.json file

Service worker is the technology that enables your app to use many Progressive Web App features, such as offline, add to homescreen, and push notifications. With proper service worker and manifest implementations, browsers can proactively prompt users to add your app to their homescreen, which can lead to higher engagement

Largest Contentful Paint marks the time at which the largest text or image is painted

Keep the server response time for the main document short because all other requests depend on it

Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this

Server latencies can impact web performance. If the server latency of an origin is high, it's an indication the server is overloaded or has poor backend performance

Sum of all time periods between FCP and Time to Interactive, when task length exceeded 50ms, expressed in milliseconds

First Contentful Paint marks the time at which the first text or image is painted

The Critical Request Chains below show you what resources are loaded with a high priority. Consider reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load