Can I use
?

let

- OTHER

Declares a variable with block level scope

Chrome

  1. ❌ 4 - 18: Not supported
  2. ❌ 19 - 40: Disabled by default
  3. ◐ 41 - 48: Partial support
  4. ✅ 49 - 130: Supported
  5. ✅ 131: Supported
  6. ✅ 132 - 134: Supported

Edge

  1. ✅ 12 - 130: Supported
  2. ✅ 131: Supported

Safari

  1. ❌ 3.1 - 9.1: Not supported
  2. ◐ 10 - 10.1: Partial support
  3. ✅ 11 - 18.0: Supported
  4. ✅ 18.1: Supported
  5. ✅ 18.2 - TP: Supported

Firefox

  1. ❌ 2 - 43: Disabled by default
  2. ✅ 44 - 131: Supported
  3. ✅ 132: Supported
  4. ✅ 133 - 135: Supported

Opera

  1. ❌ 9 - 12.1: Not supported
  2. ❌ 15 - 27: Disabled by default
  3. ◐ 28 - 35: Partial support
  4. ✅ 36 - 113: Supported
  5. ✅ 114: Supported

IE

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

Chrome for Android

  1. ✅ 131: Supported

Safari on iOS

  1. ❌ 3.2 - 9.3: Not supported
  2. ◐ 10 - 10.3: Partial support
  3. ✅ 11 - 18.0: Supported
  4. ✅ 18.1: Supported
  5. ✅ 18.2: Supported

Samsung Internet

  1. ◐ 4: Partial support
  2. ✅ 5 - 25: Supported
  3. ✅ 26: 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 - 4.4.4: Not supported
  2. ✅ 131: Supported

Firefox for Android

  1. ✅ 132: Supported

QQ Browser

  1. ✅ 14.9: Supported

Baidu Browser

  1. ✅ 13.52: Supported

KaiOS Browser

  1. ✅ 2.5: Supported
  2. ✅ 3: Supported
Resources:
MDN Web Docs - let
Variables and Constants in ES6