Sidecar or Universal Control keeps disconnecting

Sidecar and Universal Control need the same Apple Account, Bluetooth, Wi-Fi and Handoff on, and devices within 10 metres. Interference and shared connections also cause drops.

Fix this with your agentCopies a prompt for Claude Code, Codex or any agent that can use Terminal.

My Mac has this problem: Sidecar or Universal Control keeps disconnecting. Read https://kilobat.app/guides/sidecar-universal-control-disconnects.md and work through it with me. Install the Kilobat CLI if it’s missing: brew install seifip/kilobat/kilobat. Run the guide’s Terminal and kilobat checks yourself and tell me what you find. List the steps only I can do. Ask before you change any setting.

Applies to: Sidecar needs macOS Catalina 10.15 and iPadOS 13 or later. Universal Control needs macOS Monterey 12.4 and iPadOS 15.4 or later.Checked: 7 November 2026

Symptoms

The iPad display goes black or returns to the iPad's Home Screen.
The pointer stops at the edge of the Mac screen.
Sidecar works for some minutes and then disconnects.
The connection drops more often in some rooms or at some times.

Likely causes

A requirement is not met. Apple asks for the same Apple Account with two-factor authentication, and Bluetooth, Wi-Fi and Handoff on.
The devices are too far apart. Apple says that the devices must be within 10 metres (30 feet). For Universal Control, it suggests about 1 metre when you troubleshoot.
A shared connection. The iPad must not share its cellular connection. The Mac must not share its internet connection.
Wireless interference. Apple says that Wi-Fi and Bluetooth interference can affect wireless Sidecar.
VPN, security software or the firewall. For Universal Control, Apple says to check VPN and security software, and Block all incoming connections.

How to check

Make sure that the Mac and the iPad use the same Apple Account with two-factor authentication.
On both devices, make sure that Bluetooth, Wi-Fi and Handoff are on.
On the iPad, make sure that Personal Hotspot does not share the cellular connection.
On the Mac, choose Apple menu > System Settings > General > Sharing. Look at Internet Sharing.

Show whether the firewall blocks all incoming connections.

/usr/libexec/ApplicationFirewall/socketfilterfw --getblockall

How to fix it

Put the devices near each other. For Universal Control, try about 1 metre.
Turn off Internet Sharing on the Mac and Personal Hotspot on the iPad.
Move the devices away from microwave ovens, cordless phones and other sources of interference.
Connect Sidecar with the iPad's USB charge cable. The iPad must trust the Mac.
Apple names the cable to keep the iPad charged. It does not say that a cable stops wireless drops.
For Universal Control, put both devices to sleep, then wake them.
For Universal Control, turn it off on each device, restart and turn it on again.
Turn off the VPN or security software for a test.
Install the latest macOS and iPadOS updates.

With Kilobat

Show the AirDrop link, which Sidecar and Universal Control use, and what uses it now.
```
kilobat airdrop
```
Kilobat's Pause for calls and games turns off this link. Sidecar and Universal Control stop during the pause.
To end a pause now, restore the link. macOS asks for an administrator password.
```
kilobat low-latency off
```
Show Bluetooth devices and whether they share 2.4 GHz with Wi-Fi.
```
kilobat bluetooth
```
Show the Wi-Fi band and channel. Then compare nearby networks on the same channel.
```
kilobat wifi
kilobat channels
```

Questions

Where do I turn on Universal Control?

On the Mac, open System Settings > Displays > Advanced. On the iPad, open Settings > General > AirPlay & Continuity > Cursor and Keyboard.

Where do I connect Sidecar?

In macOS Ventura 13 and later, open System Settings > Displays. Click the iPad at the top.

How many devices can Universal Control use?

Apple says up to two other nearby Mac or iPad devices.

Sources

Checked on 7 November 2026.