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

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

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

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

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

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

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

This is the largest contentful element painted within the viewport

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)

First CPU Idle marks the first time at which the page's main thread is quiet enough to handle input. [Learn more](https://web.dev/first-cpu-idle/).

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

Estimated Input Latency is an estimate of how long your app takes to respond to user input, in milliseconds, during the busiest 5s window of page load. If your latency is higher than 50 ms, users may perceive your app as laggy

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

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

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

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

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

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

Large JavaScript libraries can lead to poor performance. Prefer smaller, functionally equivalent libraries to reduce your bundle size

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

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

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

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

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

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

Estimated Input Latency is an estimate of how long your app takes to respond to user input, in milliseconds, during the busiest 5s window of page load. If your latency is higher than 50 ms, users may perceive your app as laggy

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

This is the largest contentful element painted within the viewport

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

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

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

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

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

Large JavaScript libraries can lead to poor performance. Prefer smaller, functionally equivalent libraries to reduce your bundle size

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

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)

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

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

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

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

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

First CPU Idle marks the first time at which the page's main thread is quiet enough to handle input. [Learn more](https://web.dev/first-cpu-idle/).

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

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

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

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

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

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