Use an iPad as a second display with Sidecar
Overview
Sidecar is a Continuity feature that extends the workspace of a Mac by using an iPad as a second display. The extended workspace allows a user to interact with different apps on the different screens, or to use the same app across both screens, but control different aspects of it. For example, when a user has the same app open on both screens, they can view their artwork on their Mac while they use Apple Pencil and an app’s tools and palettes on iPad.
Requirements and expected behavior
Sidecar works with recent Mac and iPad models. Both devices need to be signed in to the same Apple Account using two-factor authentication. For more information, see the Apple Support article Use an iPad as a second display for a Mac.
A user connects the iPad wirelessly or over USB:
Wireless: Both devices need to be within 30 feet (10 meters) of each other, with Bluetooth, Wi-Fi, and Handoff turned on. The iPad can’t be sharing its cellular connection, and the Mac can’t be sharing its internet connection.
USB: Set the iPad to trust the Mac.
After connecting the iPad to the Mac, the iPad extends or mirrors the Mac desktop. The user moves Mac windows to the iPad, uses the sidebar and Touch Bar controls shown on the iPad screen, and points, selects, or draws with Apple Pencil. Switching to an iPad app suspends the Sidecar session until the user switches back to it.
Reported behavior
A user may report that the iPad doesn’t appear as a display option on the Mac, or that the connection drops during a session. A wireless session may lag or freeze, the Touch Bar may not appear on the iPad, or Apple Pencil input may not register.
Isolating the issue
First determine whether the user is connecting wirelessly or over USB, then confirm the devices meet the requirements.
A wireless connection depends on proximity and a clean wireless environment. Wireless interference can degrade a session even when the devices meet every requirement, so if you suspect interference, try a USB connection. For more information, see the Apple Support article Resolve Wi-Fi and Bluetooth issues caused by wireless interference.
A USB connection depends on the iPad and Mac trusting each other. Disconnecting and reconnecting can make the trust prompts reappear on both devices.
Confirm the user wants Sidecar rather than Universal Control. Sidecar shows the Mac’s desktop and apps on the iPad; Universal Control lets one keyboard, mouse, or trackpad control a Mac and a nearby iPad while each keeps its own screen and apps. For more information, see the Apple Support article Universal Control: Use a single keyboard and mouse between Mac and iPad.
Troubleshooting
Install the latest macOS and iPadOS updates on both devices.
Make sure both devices are awake, unlocked, and signed in to the same Apple Account.
For a wireless session, confirm that Bluetooth, Wi-Fi, and Handoff are turned on and that the devices are close together, and turn off any connection sharing on either device.
Connect the iPad to the Mac with a USB cable to rule out wireless interference and keep the iPad charged. Make sure the iPad is set to trust the Mac.
If the trust prompt doesn’t appear or the Mac doesn’t accept it, reset Location & Privacy on the iPad (Settings > General > Transfer or Reset iPad > Reset > Reset Location & Privacy) so the prompt appears again on the next connection. For more information, see the Apple Support article About the ‘Trust This Computer’ alert message on your iPhone, iPad, or iPod touch.
If the Touch Bar doesn’t appear on the iPad, choose Apple menu > System Settings, click Desktop & Dock in the sidebar, then turn on “Displays have separate Spaces.”
Restart both devices.
If a wireless session degrades:
Use the Sidecar monitor in Wireless Diagnostics on the Mac.
Open Wireless Diagnostics, then choose Window > Sidecar to check the live connection.
Weak peer signal strength points to distance or obstructions; high channel congestion or rising transmit failures point to wireless interference. A USB connection avoids the problem.
When the cause isn’t clear, click Collect Logs to save a report to
/private/var/tmp(aWirelessDiagnostics_*.tar.gzfile) for the network team to analyze.
Managed environments
Device management can restrict Continuity features that Sidecar relies on. Restricting Handoff prevents a wireless Sidecar connection. Device management can restrict other Continuity features, such as AirDrop and AirPlay.
On a Mac, the Allow accessory connections restriction controls whether new accessories connect to a locked Mac. On a supervised iPad, the USB Restricted Mode restriction controls whether accessories connect. For more information, see Manage accessory access to Apple devices in Apple Platform Deployment.
When any of these restrictions apply, Sidecar may not work even though the Mac and iPad otherwise qualify. To confirm an organization’s policies, check with the device management service administrator.