In defense of polyfills

If you’re a web developer, you may find the title baffling. “Polyfills need defending? Who’s against them?!” you might ask. Two weeks ago, I’d be in the same boat. Polyfills and I go way back. I dug up a JSConf EU talk of mine from 2011 on exactly this topic. Trying not to think about how young I look here 😅 One of the few opinions I have held strongly over the years is that polyfills are a net positive for the Web, and the good outweighs the rare failure cases where polyfills became too popular, too soon, and restricted the design space for the native API. As with most things in life, it’s all about the cost-benefit. We don’t stop flying planes because crashes happen. We do a post-mortem and figure out how we can prevent the same accident from happening again. And crucially, the point of a post-mortem is to find the root cause — not to ground the entire fleet. Don’t get me wrong, concerns about polyfills are well-intentioned. They come from implementors and standards folks who want…