Now USB-C enables HDMI output without dongles

HDMI Licensing

A simple USB-C-to-HDMI cable will now replace the $70 dongles which currently exist, though the source device will need to have been designed to output HDMI via USB-C. According to HDMI Licensing it's not backwards compatible with existing devices or upgradeable via software.

Called "HDMI Alt Mode" the new standard supports up to HDMI 1.4b which means resolutions up to 4K, Audio Return Channel (ARC), 3D, HDMI Ethernet Channel, and Consumer Electronic Control (CEC).

Unfortunately the cable won't support HDR content or 4K streaming services which require the newer HDMI 2.2 standard.