When realme shows a 320W charger that fully charges a smartphone in 4 minutes, it's hard to call 15W or 20W fast charging. However, Google had a different point of view until recently — at least until the release of the new Pixel 9 series.
The founder of the APKMirror portal Artem Rusakovsky noticed that his Pixel 9 Pro XL does not display a message about fast charging, even when connecting sufficiently powerful adapters. He used 60W and 45W adapters, but neither of them could provide more than 18W of power to the smartphone.
According to other users' reviews, Google's proprietary 45W adapter and some other chargers can achieve this , so that the smartphone displays a message about fast charging.
Pixel 9 does not display a message about fast charging when connecting an adapter with a power of about 11.5 W.
This is due to changes that Google contributed to Android this year. Previously, the system on Pixel devices considered fast charging anything over 7.5W, as seen in the Pixel 7 Pro photo above. But the company recently raised this threshold to 20W.
Thus, Google now considers anything above 20W fast charging.