Can I use
?

SPDY protocol

- UNOFF

Networking protocol for low-latency transport of content over the web. Superseded by HTTP version 2.

Chrome

  1. 4 - 50: Supported
  2. 51 - 108: Not supported
  3. 109: Not supported
  4. 110 - 112: Not supported

Edge

  1. 12 - 108: Not supported
  2. 109: Not supported

Safari

  1. 3.1 - 7.1: Not supported
  2. 8 - 12: Supported
  3. 12.1 - 16.2: Supported
  4. 16.3: Supported
  5. TP: Supported

Firefox

  1. 2 - 12: Not supported
  2. 13 - 50: Supported
  3. 51 - 108: Not supported
  4. 109: Not supported
  5. 110 - 111: Not supported

Opera

  1. 9 - 12: Not supported
  2. 12.1 - 39: Supported
  3. 40 - 41: Not supported
  4. 42: Supported
  5. 43: Not supported
  6. 44: Supported
  7. 45 - 91: Not supported
  8. 92: Not supported

IE

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

Chrome for Android

  1. 109: Not supported

Safari on iOS

  1. 3.2 - 7.1: Not supported
  2. 8 - 12.1: Supported
  3. 12.2 - 16.2: Supported
  4. 16.3: Supported

Samsung Internet

  1. 4: Supported
  2. 5 - 18.0: Not supported
  3. 19.0: Not supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12: Not supported
  2. 12.1: Supported
  3. 72: Not supported

UC Browser for Android

  1. 13.4: Not supported

Android Browser

  1. 2.1 - 2.3: Not supported
  2. 3 - 4.4.4: Supported
  3. 109: Not supported

Firefox for Android

  1. 107: Not supported

QQ Browser

  1. 13.1: Not supported

Baidu Browser

  1. 13.18: Not supported

KaiOS Browser

  1. 2.5: Supported

See also support for HTTP2, successor of SPDY.

Resources:
SPDY whitepaper
Wikipedia