Design
- Top-notch build quality
- The polished all-metal back of the Redmi 4 makes this phone look more premium than its predecessor (and actually more similar to the more expensive Redmi Note 4)
- Compact, and quite usable with just one hand - fits well in the hand
- Fingerprint sensor works well, and is conveniently located
Display
- Nice 5-inch HD (720x1280) IPS display with 2.5D curved-edge glass - bright, sharp, and with decent viewing angles
Software
- Xiaomi's MIUI skin is one of the more refined Android UIs - it is clean, polished, and has a bunch of added functionality - Dual Apps, Quick Ball, One-handed mode, Child Mode, Second Space
Performance
- Decent overall performance - on par with those of other phones powered by the Snapdragon 430 series processor
- Good video playback performance
Camera
- Nice attention to detail overall - such as a protective ring around the camera lens
- Decent rear camera - a definite improvement over the Redmi 3S - is quick at focusing, and images are fairly detailed and sharp
- Video recording at 720p and 1080p is decent too
- Decent front camera - pictures taken in good light have a good amount of detail and decent colour tone
- Camera performance is improved, but ordinary low-light shots and slow processing in HDR mode still leave something to be desired
Audio
- Decent call quality
- Good audio quality
Battery
- Excellent battery life - with moderate use, lasts up to 2 days - there are also power saving modes to help squeeze more life out of each charge