Currently, there are only 12 smartphones on the list with Google Pixel 3 and Samsung Galaxy Note 9 leading the pack, both with the same 92 score. According to details provided by DxOMark, the testing is pretty much done the same as on the main camera test protocol, capturing over 1500 sample images and several hours of video tests and scenes, with some minor adjustments by taking into account the way people use the front camera.
While Pixel 3 and Note 9 are on top of the list, Xiaomi's Mi MIX 3 also got a decent 84 score, trailed closely by iPhone XS Max and Galaxy S9 Plus, with scores of 82 and 81.
Huawei's Mate 20 Pro and P20 Pro have been holding the top of the list for the main/rear camera with a 109 score for quite some time, but they did not do that well when it comes to front camera test, scoring just 75 and 72.
Overall score goes to Galaxy Note 9, which has a somewhat higher score main/rear camera score than Google Pixel 3.
You can check out more details over at the DxOMark dedicated post.