Use your iPad as a second display for your Mac
With Sidecar, you can use your iPad in landscape orientation as a second display for your Mac. Like any second display, you can extend your desktop by showing different apps or windows on your iPad, or instead make it show the same ones you see on your Mac.
Note: Sidecar is a Continuity feature. To use Continuity features, your devices must have Wi-Fi and Bluetooth turned on and meet system requirements. See the Apple Support article System requirements for Continuity on Mac, iPhone, iPad, iPod touch and Apple Watch.
Set Sidecar options
Make sure you’re signed in with the same Apple ID on your Mac and iPad.
On your Mac, choose Apple menu
> System Preferences, then click Sidecar.Set options for showing the sidebar and the Touch Bar on iPad, and for using Apple Pencil.
If you’re not already connected to your iPad, click the “Connect to” pop-up menu, then choose your iPad.
You can also connect from the Airplay menu
in the menu bar or, in Displays preferences, from the AirPlay Display pop-up menu.You don’t need to connect your iPad to your Mac with a cable to use Sidecar.
Use Sidecar
If you’re not already connected to your iPad, click the Airplay menu
in the menu bar on your Mac, then select your iPad.The Sidecar menu
appears in the menu bar. You can easily change how you work with iPad from the Sidecar menu at any time. For example, switch between using iPad as a mirrored or separate display, or show or hide the sidebar or Touch Bar on iPad.Do any of the following:
Move windows from Mac to iPad: Drag a window to the edge of the screen until the pointer appears on your iPad. Or while using an app, choose Window > Move Window to iPad.
Move windows from iPad to Mac: Drag a window to the edge of the screen until the pointer appears on your Mac. Or while using an app, choose Window > Move Window Back to Mac.
Use the sidebar on iPad: With your finger or Apple Pencil, tap icons in the sidebar to show or hide the menu bar
, the Dock 
or the keyboard 
. Or tap one or more modifier keys, such as Ctrl 
, to use keyboard shortcuts.Use the Touch Bar on iPad: With your finger or Apple Pencil, tap any button in the Touch Bar. The buttons available vary depending on the app or task.
Use Apple Pencil on iPad: With your Apple Pencil, tap to select items such as menu commands, tickboxes or files. If your Apple Pencil supports it (and you set the option in Sidecar preferences), you can double-tap the lower section of your Apple Pencil to switch drawing tools in some apps. See the Apple Support article Use Apple Pencil with your iPad or iPad Pro.
Use gestures on iPad: Use basic gestures, such as tap, swipe, scroll and zoom, as well as gestures for entering and editing text. See the iPad User Guide.
Switch between the Mac desktop and the iPad on iPad: Swipe up from the bottom edge of your iPad with one finger to show the iPad Home screen. To show the iPad Dock, swipe up and pause. To show the iPad App Switcher, swipe up and pause in the centre of the screen. To return to the Mac desktop, swipe up, then tap the Sidecar icon
.
When you’re ready to stop using your iPad, click the Disconnect icon
at the bottom of the sidebar on iPad.You can also disconnect from the Sidecar menu in the menu bar or in Sidecar or Displays system preferences.