Is the Phone Link app safe and reliable?

Phone Link is an official Microsoft app and is generally safe to use. 

First, make sure the Windows app is Phone Link published by Microsoft Corporation, and the phone app is Link to Windows, also published by Microsoft. Avoid similarly named apps from unknown developers or unofficial download sites.

The app is usually reliable, but available features depend on the phone model. Connections can occasionally stop working because of Wi-Fi, Bluetooth or phone battery-saving settings. It is useful for transferring files, but it should not be treated as a backup. After moving an important file, confirm that the copy opens correctly before deleting the original.