Gregory's Server📢 New post: The State of ES5 on the Web.
For years, we defaulted to transpiling to ES5 in order to support IE. But is that still necessary?
I took a look at the data to find out, and I'll just say that the results were *actually* quite surprising! 🙀
https://philipwalton.com/articles/the-state-of-es5-on-the-web/
@philipwalton Fascinating, thank you for this!
Is it possible that some sites served ES6+ code because they recognised Chrome (which HTTP Archive uses for the crawl) BUT would serve purely ES5 code to (say) IE11?
I've no idea how common this would be in practice, but I remember plenty of recommendations in the past about doing this sort of thing.
@philipwalton Very interesting investigation!
What I feel like I'm missing is how many users are in practice still using browsers without ES2015+ support.
I know @ljharb knows about similar Node.js data, maybe they also know about browser usage?
I otherwise completely agree that the state where websites think they support ES5 browsers but don't is a problem.
@philipwalton Do you know of any bundle analysis tooling that covers this ES5/6 gap? I also think about stuff like SVGs that sneak into bundles and tanks performance. Or like Jake's post about a setTimeout in an IFFE. Is there a Lighthouse for bundles?
Most bundle analyzers I see are just tree-graphs, which is helpful but not critical about how much "over-compiled" code has leeched into your build.