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Info about Sidecar - Use your iPad as a second display for your Mac with Sidecar – Apple Support

Sidecar system requirements

Sidecar requires a compatible Mac using macOS Catalina and a compatible iPad using iPadOS 13:

Mac using macOS Catalina

• MacBook Pro introduced in 2016 or later
• MacBook introduced in 2016 or later
• MacBook Air introduced in 2018 or later
• iMac introduced in 2017 or later, plus iMac (Retina 5K, 27-inch, Late 2015)
• iMac Pro
• Mac mini introduced in 2018 or later
• Mac Pro introduced in 2019
•   

iPad using iPadOS 13

• iPad Pro: all models
• iPad (6th generation) or later
• iPad mini (5th generation)
• iPad Air (3rd generation)

Additional requirements

• Both devices must be signed in to iCloud with the same Apple ID using two-factor authentication.
• To use Sidecar wirelessly, both devices must be within 10 metres (30 feet) of each other and have Bluetooth, Wi-Fi and Handoff turned on. Also make sure that the iPad is not sharing its cellular connection and the Mac is not sharing its Internet connection.
• To use Sidecar over USB, make sure that your iPad is set to trust your Mac.

• Is your Mac using MacOS Catalina?
• Are both devices using the same Apple ID?
• Are both using two-factor authentication?
• Are both using Handoff?
• Do both have Bluetooth on?
• Are both using the same wi-fi?
• Are both within thirty feet?