The Alcatel Idol 4 shares the same build as the more premium Idol 4S. The metal frame and Gorilla Glass 3 at the front and back feel just as nice as the phone's bigger brother.
What's changed is the display, which is 5.2" IPS LCD panel with 1080p resolution and the chipset is a Snapdragon 617 with either 2GB of 3GB of RAM depending on the model. The Boom Key is here as well, as is the reversibility options and stereo speakers. Due to the smaller size, the phone is a tad lighter at 130 grams.
At the back, there's a 13MP camera, which records 1080p videos, while the 8MP front-facer with LED combo from the Idol 4S is unchanged.
In case you're wondering, Alcatel is keeping the same packaging for the Idol 4 as the Idol 4S. Getting the phone will also get you the cool retail box that converts to a VR headset.