http://www.techradar.com/news/samsung-galaxy-s9-could-have-even-less-bezel-than-the-galaxy-s8

The Samsung Galaxy S8 is almost all screen on the front, but there is a bit of bezel above and below it, however that might be almost entirely eliminated on the Samsung Galaxy S9.

A tipster has told SamMobile that there could be a 90% screen-to-body ratio on the Galaxy S9, up from around 84% on the Galaxy S8.