File System Access API

- UNOFF

API for manipulating files in the device's local file system (not in a sandbox).

Chrome

  1. 4 - 73: Not supported
  2. 74 - 85: Disabled by default
  3. 86 - 124: Partial support
  4. 125: Partial support
  5. 126 - 128: Partial support

Edge

  1. 12 - 18: Not supported
  2. 79 - 85: Disabled by default
  3. 86 - 124: Partial support
  4. 125: Partial support

Safari

  1. 3.1 - 15.1: Not supported
  2. 15.2 - 17.4: Partial support
  3. 17.5: Partial support
  4. 17.6 - TP: Partial support

Firefox

  1. 2 - 110: Not supported
  2. 111 - 125: Partial support
  3. 126: Partial support
  4. 127 - 129: Partial support

Opera

  1. 9 - 60: Not supported
  2. 62 - 71: Disabled by default
  3. 72 - 108: Partial support
  4. 109: Partial support

IE

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

Chrome for Android

  1. 124: Partial support

Safari on iOS

  1. 3.2 - 15.1: Not supported
  2. 15.2 - 17.4: Partial support
  3. 17.5: Partial support
  4. 17.6: Partial support

Samsung Internet

  1. 4 - 23: Not supported
  2. 24: Not supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 80: Partial support

UC Browser for Android

  1. 15.5: Not supported

Android Browser

  1. 2.1 - 4.4.4: Not supported
  2. 124: Partial support

Firefox for Android

  1. 125: Not supported

QQ Browser

  1. 14.9: Not supported

Baidu Browser

  1. 13.52: Not supported

KaiOS Browser

  1. 2.5: Not supported
  2. 3: Not supported
Resources:
Chrome blog post
Explainer
Firefox position: harmful
Web.dev blog post