EStimator.dev: the modern JavaScript savings calculator
Find out how much smaller your JavaScript could be.
Find out how much smaller your JavaScript could be.
How and when did I get to the point where I would consider a page weight of 4 MB on a large page and 500 KB on a small page normal?
This isn’t just a well-earned rant from Manuel. I mean, it *is that, but it’s also packed with practical performance advice.
It’s time for a look at the state of the web when it comes to JavaScript usage. Here’s the report powered by data from HTTP Archive:
JavaScript is the most costly resource we send to browsers; having to be downloaded, parsed, compiled, and finally executed. Although browsers have significantly decreased the time it takes to parse and compile scripts, download and execution have become the most expensive stages when JavaScript is processed by a web page.
Sending smaller JavaScript bundles to the browser is the best way to reduce download times, and in turn improve page performance. But how much JavaScript do we really use?
When it comes to frameworks and UI libraries, there are some interesting numbers. Given the volume of chatter in the dev world, you’d be forgiven for thinking that React is used on the majority of websites today. The real number? 4.6% of websites. That’s less than the number of websites using CSS custom properties.
This is reminding me of what I wrote about dev perception.
Following on from that proposal for a browser feature that I linked to yesterday, Tim thinks through all the permutations and possibilities of user agents allowing users to throttle resources:
If a limit does get enforced (it’s important to remember this is still a big if right now), as long as it’s handled with care I can see it being an excellent thing for the web that prioritizes users, while still giving developers the ability to take control of the situation themselves.
I remember Jason telling me about this weird service worker caching behaviour a little while back. This piece is a great bit of sleuthing in tracking down the root causes of this strange issue, followed up with a sensible solution.
This is an interesting use of voodoo magic (or “machine learning” as we call it now) by Google to interpolate data in a small image to create a larger version. A win for performance.