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.

IE

  1. 5.5 - 10
  2. 11

Edge

  1. 12 - 14
  2. 15 - 18
  3. 79 - 81
  4. 83

Firefox

  1. 2 - 5
  2. 6 - 53
  3. 54 - 77
  4. 78
  5. 79 - 80

Chrome

  1. 4 - 20
  2. 21 - 50
  3. 51 - 81
  4. 83
  5. 84 - 86

Safari

  1. 3.1 - 7
  2. 7.1 - 9.1
  3. 10 - 13
  4. 13.1
  5. 14 - TP

Opera

  1. 9 - 12.1
  2. 15 - 37
  3. 38 - 68
  4. 69

iOS Safari

  1. 3.2 - 6.1
  2. 7 - 9.3
  3. 10 - 13.3
  4. 13.4
  5. 14.0

Opera Mini

  1. all

Android Browser

  1. 2.1 - 4.3
  2. 4.4 - 4.4.4
  3. 81

Blackberry Browser

  1. 7
  2. 10

Opera Mobile

  1. 10 - 12.1
  2. 46

Chrome for Android

  1. 81

Firefox for Android

  1. 68

IE Mobile

  1. 10
  2. 11

UC Browser for Android

  1. 12.12

Samsung Internet

  1. 4
  2. 5 - 11.2
  3. 12.0

QQ Browser

  1. 10.4

Baidu Browser

  1. 7.12

KaiOS Browser

  1. 2.5

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