1 Answer. Browsers cannot read JSX because there is no inherent implementation for the browser engines to read and understand it. You can use babel to transform your jsx into native javascript and HTML which browser can understand.

Are there any browsers with a JSX compiler built in?

Answer. Unfortunately, there are no browsers (currently) with a JSX compiler built in.

How different is React's ES6 syntax when compared to ES5?

Performance: based on performance, ES6 has a higher performance than others due to the new features and the shorthand storage implementation whereas ES5 has a lower performance due to non-presence of features.