Knowledge base
Compatibility and syncing
Social media popularised hashtags and we are used to tagging Twitter tweets with them or adding them to Instagram posts. Now they can be added to notes in the Apple Notes app. A hashtag is simply a hash symbol followed by a keyword, like #recipe. When they are added to notes, you can instantly find all notes with a specific hashtag by selecting it.
Hashtags added to notes created on the Mac automatically sync to other Macs, the iPhone and iPad. Create them on a Mac and you will see them on your iPhone, except for devices running old versions of macOS and iOS. Not only are hashtags not visible, the whole note is hidden. Don’t add tags if you use old devices.