What metrics to use to evaluate website loading speed

[jakariabd@]

What is page load speed? This is the time from the moment a user enters a site until it is fully loaded.

This would be the case if the site loaded in two stages: request - loading.

But in reality, loading looks like this:

What Should Be the Loading Speed ​​of a Website [and How to Increase It]

Various resources are gradually loaded: HTML, styles, scripts, images, fonts, videos, etc. And often the user does not need to wait for the page to fully load to fully interact with it.

That is why there are more than 15 metrics to evaluate the site loading speed. Let's consider those that directly affect the user experience.


Time To First Byte (TTFB) is the time from the moment a request is sent to the server until the moment the user's browser receives the first byte of information.

This metric consists of the following components:

time spent sending a request to the server;
time spent processing and generating a response;
the time it takes for a response to travel back to the user.
From a user's perspective, TTFB is a "white" screen while waiting for the site to load.

What Should Be the Loading Speed ​​of a Website [and How to Increase It]

First Content Paint (FCP)
First Contentful Paint (FCP) is the time from the moment a request is sent to norway phone number material the server until the moment the browser displays the first pixel of content on the screen.

This metric is critically important because displaying content (even minimally) is a signal to the user that the site is loading. If the FCP is high, the user will think the site is not responsive and will leave.

Time to load sufficient portion of content (FMP)
First Meaningful Paint (FMP) is the time from when a request is sent to the server until the user sees enough content to begin interacting with the page.

Depending on the way the site content is displayed, the FMP can be the same as the FCP or higher. The first option is preferable - in this case, when the first rendering occurs, the user immediately sees a significant part of the content (for example, the title and the first paragraph, and not the picture frame or background).