Window.devicePixelRatio

- WD

Read-only property that returns the ratio of the (vertical) size of one physical pixel on the current display device to the size of one CSS pixel.

Chrome

  1. 4 - 105: Supported
  2. 106: Supported
  3. 107 - 109: Supported

Edge

  1. 12 - 105: Supported
  2. 106: Supported

Safari

  1. 3.1 - 15.6: Supported
  2. 16.0: Supported
  3. 16.1 - TP: Supported

Firefox

  1. 2 - 17: Not supported
  2. 18 - 104: Supported
  3. 105: Supported
  4. 106 - 107: Supported

Opera

  1. 9 - 11.5: Not supported
  2. 11.6 - 90: Supported
  3. 91: Supported

IE

  1. 5.5 - 10: Not supported
  2. 11: Supported

Chrome for Android

  1. 106: Supported

Safari on iOS

  1. 3.2 - 15.6: Supported
  2. 16.0: Supported
  3. 16.1: Supported

Samsung Internet

  1. 4 - 17.0: Supported
  2. 18.0: Supported

Opera Mini

  1. all: Supported

Opera Mobile

  1. 10 - 11.5: Not supported
  2. 12 - 12.1: Supported
  3. 64: Supported

UC Browser for Android

  1. 13.4: Supported

Android Browser

  1. 2.1 - 4.4.4: Supported
  2. 106: Supported

Firefox for Android

  1. 105: Supported

QQ Browser

  1. 13.1: Supported

Baidu Browser

  1. 13.18: Supported

KaiOS Browser

  1. 2.5: Supported

As the page is zoomed in the number of device pixels that one CSS pixel covers increases, and therefore the value of devicePixelRatio will also increase.

Resources:
MDN Web Docs - devicePixelRatio