Show your Chromebook screen on your monitor

  1. At the bottom right, select the time.
  2. Select Settings .
  3. In the "Device" section, select Displays.
  4. Select Mirror Built-in Display. This option will appear when your monitor is connected.

Tip: To view your Chromebook screen only on your monitor, press and hold Decrease brightness .

Adjust your screens

  1. At the bottom right, select the time.
  2. Select Settings .
  3. In the "Device" section, select Displays.
  4. To adjust your Chromebook screen, select Built-in Display. To adjust your monitor screen, select the name of the monitor.
    • Make items on your screen smaller or larger: In the "Display size" section, choose an option.
    • Rotate the screen: In the "Orientation" section, choose an option.
  5. [Optional] Under your monitor tab, you can also:
    • Change screen sharpness: In the "Resolution" section, choose an option.
    • Change frequency of screen updates: Choose a higher refresh rate to refresh content on the screen faster.

Tip: To quickly move windows or apps from one screen to another, on your keyboard, press Search  + Alt + m or Launcher  + Alt + m.

Use an adapter to connect your Chromebook to a monitor

Sometimes you need an adapter cable to connect your Chromebook to a monitor. To learn what type of cable you need, check the instructions included with your Chromebook.

  1. Find the display output and input ports on your Chromebook. (If you’re not sure which ports to use, check the instructions included with your Chromebook.)
  2. Use these two ports to find the correct adapter (ex. DisplayPort to HDMI).
  3. Plug the adapter into the monitor, then into your Chromebook.

https://support.google.com/chromebook/answer/1060909?hl=en