What is First Input Delay (FID) and Total Blocking Time (TBT)?
What is FIDTBT?
First Input Delay (FID) measures the time between a user's first interaction on a page (clicking a button or link) and the time the browser responds and performs the intended function.
In simple terms, First Input Delay tells us how long the user has to wait for the interface to respond after the first click.
This question basically asks how fast is the page interactive? In ecuador mobile database other words, when a user clicks something, a button, or a JavaScript event, how quickly can the browser start processing and producing results? When you click something and nothing happens or it happens very slowly, it's not a good experience.
Web.dev tells us that the main cause of input lag is that the browser's main thread is busy doing other things and can't respond to the user immediately.
Typically, this is due to lengthy Javascript-related tasks that take a significant amount of time to execute.
Along with Largest Contentful Paint (LCP) and Cumulative Layout Shift (CLS) , First Input Delay is one of the three core web elements that Google emphasized in its Page Experience Update launched in the summer of 2021.
In this update, Google confirmed that three core web vital signs will be part of its ranking algorithm. Therefore, you want your pages to be in the following “good” range according to Google when measuring their core web vital signs.