- [Instructor] There's a useful mnemonic device
you can use to remember how to achieve
the best possible performance
for your website or application.
PRPL, or P-R-P-L, referring to the PRPL pattern.
This is an acronym that stands for
push or preload the most important resources,
render the initial route as soon as possible,
pre-cache remaining assets,
and lazy load other routes and non-critical assets.
This pattern has become the industry standard benchmark
for web performance for two main reasons.
It was developed by the leading industry experts
on performance and it just makes sense.
If we push or preload important resources to the browser
using server push for the initial load
and service workers in the next round,
the application will run faster.
If we render the initial route as soon as possible
by serving the browser with critical CSS and JavaScript,
the perceived performance of the application
will be improved.
If we pre-cache remaining assets
so they are available when the browser needs them,
the application performance will be dramatically improved.
And finally, if we lazy load all non-critical assets
so they only load when they are actually needed,
we reduce the time to initial load
and save the visitor from wasting their bandwidth
on assets they will never use.
As you make your way through this course,
keep the PRPL pattern in mind
because almost everything that we're going to cover
fits into one of these steps,
push our preload, render, pre-cache, and lazy load.