JavaScript versions

JavaScript, properly known as ECMAScript is standard ECMA-262. The versions are shown in the table below
editiondate publishedname
4AbandondECMAScript 4
5December 2009ECMA-262 5th Edition
5.1June 2011ECMA-262 5.1 Edition - fully aligned with ISO/IEC 16262:2011
6June 2015ECMAScript 2015 (ES2015)
7June 2016ECMAScript 2016 (ES2016)
8June 2017ECMAScript 2017 (ES2017)
9June 2018ECMAScript 2018 (ES2018)
10June 2019ECMAScript 2019 (ES2019)

This list provides links to the formal specifications of the current and all historical Javascript versions

Transpilers typically comple to ES5 (i.e. ECMA-262 5th Edition) which is supported by all modern browsers although sometimes all the way down to ES3 (which is supported by all browsers). The transpilation target is configurable in, e.g. Babel.