ECMAScript 2015 (ES6)

- OTHER

Support for the ECMAScript 2015 specification. Features include Promises, Modules, Classes, Template Literals, Arrow Functions, Let and Const, Default Parameters, Generators, Destructuring Assignment, Rest & Spread, Map/Set & WeakMap/WeakSet and many more.

Chrome

  1. 4 - 20: Not supported
  2. 21 - 50: Partial support
  3. 51 - 121: Supported
  4. 122: Supported
  5. 123 - 125: Supported

Edge

  1. 12 - 14: Partial support
  2. 15 - 18: Supported
  3. 79 - 121: Supported
  4. 122: Supported

Safari

  1. 3.1 - 7: Not supported
  2. 7.1 - 9.1: Partial support
  3. 10 - 17.3: Supported
  4. 17.4: Supported
  5. TP: Supported

Firefox

  1. 2 - 5: Not supported
  2. 6 - 53: Partial support
  3. 54 - 122: Supported
  4. 123: Supported
  5. 124 - 126: Supported

Opera

  1. 9 - 12.1: Not supported
  2. 15 - 37: Partial support
  3. 38 - 107: Supported
  4. 108: Supported

IE

  1. 5.5 - 10: Not supported
  2. 11: Partial support

Chrome for Android

  1. 122: Supported

Safari on iOS

  1. 3.2 - 6.1: Not supported
  2. 7 - 9.3: Partial support
  3. 10 - 17.3: Supported
  4. 17.4: Supported

Samsung Internet

  1. 4: Partial support
  2. 5 - 22: Supported
  3. 23: Supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 80: Supported

UC Browser for Android

  1. 15.5: Supported

Android Browser

  1. 2.1 - 4.3: Not supported
  2. 4.4 - 4.4.4: Partial support
  3. 122: Supported

Firefox for Android

  1. 123: Supported

QQ Browser

  1. 14.9: Supported

Baidu Browser

  1. 13.52: Supported

KaiOS Browser

  1. 2.5: Partial support
  2. 3: Supported

As ES6 refers to a huge specification and browsers have various levels of support, "Supported" means at least 95% of the spec is supported. "Partial support" refers to at least 10% of the spec being supported. For full details see the Kangax ES6 support table.

Resources:
ES6 New features: overview and comparisons
Exploring ES6 (book)
Polyfill for all possible ES2015 features is available in the core-js library
Sub-features:
Typed Arrays
let
Arrow functions
Rest parameters
ES6 Number
Proxy object
ES6 Template Literals (Template Strings)
ES6 classes
ES6 Generators
String.prototype.includes