Polyfill.io

Polyfill.io is a service which makes web development less frustrating by selectively polyfilling just what the browser needs. Polyfill.io reads the User-Agent header of each request and returns polyfills that are suitable for the requesting browser. There are lots of differing browsers and browser versions in use throughout the world, each one has a slightly different set of features to the rest. This can make developing for browsers a difficult task. The latest versions of the popular browsers can do lots of things which older browsers can not – but you may still have to support the older browsers. Polyfill.io makes it simpler to support differing browsers by attempting to recreate the missing features with polyfills: You can make use of the latest and greatest features in browsers which support them, and in those that do not.