With Fast Pair, Google wants to facilitate the pairing of Bluetooth accessories with Android smartphones and tablets. And in 2019, this feature will be extended to Chromebooks to make the transition from one device to another completely transparent. The management of Bluetooth is a real pain. If you use several Bluetooth accessories connected to a device (a connected watch, a speaker), or conversely that you tried to pair an accessory to several terminals (like a wireless headset linked to a smartphone and a PC), you may quickly have to disconnect Bluetooth and restart a search for nearby Bluetooth connections regularly.
Well aware of this problem, Google announced Fast Pair during the presentation of its first headphones, Pixel Buds. This is a protocol that allows pairing common to all compatible devices associated with the same Google Account. So, if you have paired a headset to a smartphone and you change it, you should in theory be able to listen to music on your new phone just by clicking on a notification.
For compatible devices only
For Google Fast Pair to work, it is necessary that the phone runs on Android 6.0 Marshmallow or later, which should not be too much trouble in 2018 since it represents 70% of smartphones and tablets outstanding at the last census.
However, the accessory to be connected must also be compatible, which is already much less obvious given the plurality of brands. Google claims to have worked with "dozens of builders" and "many of them will be offering Fast Pair compatible devices in the coming months."
Finally, note that Fast Pair will be compatible with Chromebooks in 2019, ensuring a little more continuity between Android and Chrome OS pending Fuchsia.