Apple’s new Watch outpaces the Pixel Watch 4 for heart rate accuracy, but its real rival is missing

TL;DR Apple’s large-scale study found the Watch Series 12 more accurate than the Pixel Watch 4 overall for heart-rate tracking. The Pixel Watch 4 matched Apple during cycling and narrowly beat it at rest under two accuracy measures. The newer Pixel Watch 5 and Galaxy Watch 9 missed the test because Apple selected competitors available by June.