## Browsers that don't support ECMAScript 6 (ES6) SignalR targets ES6. For browsers that don't support ES6, transpile the library to ES5. For more information, see [Getting Started with ES6 – Transpiling ES6 to ES5 with Traceur and Babel](https://weblogs.asp.net/dwahlin/getting-started-with-es6-%E2%80%93-transpiling-es6-to-es5).