[1] Improvements include expanded stylus-related functionality, an optically stabilized rear camera, 1440p quad-HD filming on the front camera, significantly increased charging rate, revised multi-windowing, and fingerprint unlocking.

The Samsung Galaxy Note 4 features a 2560×1440 Quad HD (“WQHD”) Super AMOLED 5.7-inch display with 2.5D damage-resistant Gorilla Glass 4 and provides a pixel density of 515 ppi (pixels-per-inch).

The Note 4 came in two variants, one powered by a 2.7 GHz quad-core Qualcomm Snapdragon 805 chipset with Adreno 420 GPU, the other powered by Samsung's ARMv8-A Exynos 7 Octa SoC with two clusters of four cores; four Cortex-A57 cores at 1.9 GHz, and four Cortex-A53 cores at 1.3 GHz, which is the same processor cluster sold for the Samsung Galaxy Note 3 in markets that mostly use or only have 3G (such as HSUPA and HSPA), and/or '2G', such as unaltered GSM and CDMA networks, similar to how the Galaxy Note 3 is sold.

[6] The memory card slot has been relocated to allow hot swapping without physical blockage by the battery.

It has a new aluminum frame design, bearing resemblance from the Samsung Galaxy Alpha, but lacks an IP67 certification (water and dust resistance), which was present in Samsung's other flagship, the Galaxy S5, released half a year earlier.

[19] Next to the wireless charging S View cover, another accessory for the device is the LED flip wallet (or LED dot case), which allows displaying the clock time through barely visible small pin holes on the front cover while closed.

A flashlight shortcut, optional analogue clock designs (next to the default, digital clock), as well as the ability to record video, a shortcut to dial contacts (phone numbers) marked as favourite, and access to the heart rate monitor, all without opening the cover, have been added.

[22][23] The Samsung Galaxy Note 4 originally shipped with Google's mobile operating system, Android, specifically KitKat 4.4.4, with its user interface modified with Samsung's custom skin named TouchWiz Nature UX 3.0.

[24][25] The device can be updated to Android 5.0.1 Lollipop in many regions, bringing a new, refined UI, and new runtime.

[29][30] The gallery software is compatible with the Air View feature that allows previewing photos from albums when hovering the stylus above it.

User reports suggest that the Exif (meta data) viewer has been removed from Galaxy Note 4.

[31][32] The main (rear-facing) camera is a 16-megapixel (5312×2988) autofocus camera with 16:9 aspect ratio image sensor (Sony Exmor RS IMX240),[33] featuring Smart OIS (optical image stabilization + software image stabilization), being the first mobile phone of the Samsung Galaxy Note series and the first original variant Samsung flagship phone to feature an optically stabilized rear camera.

Like the Galaxy S5, its rear camera supports high dynamic range (HDR) video recording with up to 1080p at 30 fps.

After the LG G3, the Galaxy Note 4 is the second mobile phone to be able to record optically stabilized 2160p (4K) video.

The first regions to receive the device were South Korea and China where it gained huge popularity.

[43] A class action lawsuit against Samsung about the eMMC problem in the United States is pending.