Can I use
?

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 - 104: Partial support
  4. ✅ 105 - 134: Supported
  5. ✅ 135: Supported
  6. ✅ 136 - 138: Supported

Edge

  1. ❌ 12 - 18: Not supported
  2. ❌ 79 - 85: Disabled by default
  3. ◐ 86 - 104: Partial support
  4. ✅ 105 - 134: Supported
  5. ✅ 135: Supported

Safari

  1. ❌ 3.1 - 18.3: Not supported
  2. ❌ 18.4: Not supported
  3. ❌ 18.5 - TP: Not supported

Firefox

  1. ❌ 2 - 136: Not supported
  2. ❌ 137: Not supported
  3. ❌ 138 - 140: Not supported

Opera

  1. ❌ 9 - 60: Not supported
  2. ❌ 62 - 71: Disabled by default
  3. ◐ 72 - 90: Partial support
  4. ✅ 91 - 116: Supported
  5. ✅ 117: Supported

IE

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

Chrome for Android

  1. ❌ 135: Not supported

Safari on iOS

  1. ❌ 3.2 - 18.3: Not supported
  2. ❌ 18.4: Not supported
  3. ❌ 18.5: Not supported

Samsung Internet

  1. ❌ 4 - 26: Not supported
  2. ❌ 27: Not supported

Opera Mini

  1. ❌ all: Not supported

Opera Mobile

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

UC Browser for Android

  1. ❌ 15.5: Not supported

Android Browser

  1. ❌ 2.1 - 4.4.4: Not supported
  2. ❌ 135: Not supported

Firefox for Android

  1. ❌ 137: 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