Mac Turn off Display when External?

How to Turn off MacBook Screen When Using External Monitor

Just go to the Apple menu and select Sleep. Once your Mac is put to sleep, you can now disconnect your external monitor and youre done.

How do I Turn off my Mac Screen when Using an External Monitor?

You can dim your Macbook's screen all the way down (just press brightness down repeatedly) and then connect the Macbook to your monitor with HDMI. Your screen will be off but the keyboard and trackpad built into the Macbook will still be on and available.

Can I Close my MacBook Pro when Using an External Monitor?

If you use an external keyboard and mouse with your Mac notebook, you can close the builtin display after you connect your external display . You might have to press a key or click your mouse to wake the external display.