Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity

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

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

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

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

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

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity

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

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

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

Minifying CSS files can reduce network payload sizes

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

This is the largest contentful element painted within the viewport

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

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

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

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

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

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

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

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

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)

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

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

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

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

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity

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

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

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

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

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

Minifying CSS files can reduce network payload sizes

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

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

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

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

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

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

This is the largest contentful element painted within the viewport

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

First Contentful Paint 3G marks the time at which the first text or image is painted while on a 3G network

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

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity

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

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

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

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

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

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)