What is "Fast Pair" Smartphone?

When using a Bluetooth device on a smartphone or PC, in principle, registration work called "pairing" is required in advance. Bluetooth audio devices such as earphones/headphones and speakers are also required to exchange audio data between the two paired devices (A2DP profile).

However, since pairing becomes a hurdle of device introduction, technology was developed to reduce the processing.

One function introduces by Apple is its AirPods, which pairing complete only by tapping the button.  The task which does this is
Apple's proprietary communication chip "W1" is in AirPods and iOS.

"Fast Pair," developed by Google, delivers the same functionality as AirPods on Android devices. Initially announced in 2017, it was exclusively for Google Pixel, but now it works on all Android devices running Android OS 6.0 / Google Play 11.7 or later.

If you are using Fast Pair, you need a compatible earphone/headphone. But if you do have a few other devices for your Android devices, you can easily connect it with just one tap.

Unlike AirPods, it does not use a dedicated IC and achieves the same function using Bluetooth LE and Google's cloud service. The next OS, Android Q, will also include the ability to display the charge case battery level and find lost earphones.

As of July 2019, it is difficult to say that there are many Fast Pair compatible earphones/headphones such as Google Pixel Buds (unreleased in Japan).

Some functions can't be work without the cooperation of the earphone/headphone maker, and it is carrying that within a few months, it's improved to a better service.