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