If you can't connect your Magic Keyboard, Magic Mouse or Magic Trackpad to your Mac
Try following these steps to resolve issues with your Magic accessories.
Turn the device off and on
Magic Mouse has a switch on the bottom of the device, and Magic Keyboard and Magic Trackpad have a switch on the back edge of the device. Slide the switch to turn the device off (no green is visible), then slide the switch back to turn the device on (green becomes visible).
Earlier Apple Wireless Keyboard and Magic Trackpad models have a power button on the right side of the device. Hold the button until the green LED on top of the device turns off, then press the button until you can see the green LED again to turn the device on.
Make sure bluetooth is turned on
Using your Mac laptop's built-in trackpad or a USB mouse, choose Apple menu > System Settings (or System Preferences), then click Bluetooth. Make sure that bluetooth is turned on.
If you don't have a USB mouse and your keyboard is connected, press Command-Space bar, enter Bluetooth File Exchange in the Spotlight search field, press the Return or Enter key, then press the Return or Enter key to turn Bluetooth on.
If you still can't turn Bluetooth on, restart your computer, then try to turn Bluetooth on again.
Connect the Lightning cable
Connect your wireless accessory to your Mac with the Lightning to USB cable or USB-C to Lightning cable, wait one minute, then disconnect the cable. This pairs the accessory with your Mac and charges the built-in battery. To check your accessory's charge level, click the Control Centre icon
in the menu bar, then click Bluetooth.
Earlier models don’t use a Lightning cable for charging, but have batteries you can replace. Find out how to pair those devices with your Mac.
Check for wireless interference
If your accessory isn't staying connected wirelessly, there may be interference with other wireless devices. Find out how to resolve Wi-Fi and Bluetooth issues caused by wireless interference.
