The phone is primarily aimed at users desiring a flagship device, in contrast to Microsoft's previous strategy of targeting developing markets with low-end hardware.

[7][8] The Lumia 950 has a polycarbonate frame with a removable back shell, allowing access to the battery as well as SIM and microSD card slots.

[12] The Lumia 950 has a 20 MP PureView-branded rear-facing camera, containing a 1/2.4 in BSI sensor with 1.12 μm pixels and phase-detection autofocus, a 6-element Carl Zeiss lens with a f/1.9 aperture and 5th-gen optical image stabilization, and a triple-LED RGB flash that can adjust to match the color of ambient light.

The camera can also capture oversampled 8 MP images, optionally with a full-resolution DNG file that enables more post-processing possibilities.

The latter supports USB OTG, enabling the use of peripherals like mice, flash drives or external microphones,[17] and USB-C fast charging.

[citation needed] The Lumia 950 was generally well-received, with most reviewers commending the high-end specifications and camera performance, but finding the design to be less "premium" than competing flagships, and the app ecosystem to be less comprehensive than Android or iOS.

The phone's design was called "practical, but not beautiful", and features like Windows Hello and Continuum were reported to be working well, albeit with some issues.

While some faults were found with the design, battery life and price, the review concluded with: "Microsoft has done an amazing job with the Lumia 950...

"[35] Matthew Miller of ZDNet described the design as "an uninspiring, simple rectangular form factor", but acknowledged the practical advantages of plastic over materials like glass or aluminum.

The Windows app ecosystem was seen as lacking in both quantity and quality compared to Android and iOS, and the reviewer expressed concern over the performance of the OS itself, although commending a number of features like "the Action Center, the awesome keyboard and predictive text engine, and reader mode in the browser".

[36] Todd Haselton of TechnoBuffalo commended the inclusion of a dedicated camera key and overall imaging capabilities, but criticized the design and said the user interface of Windows 10 Mobile "feels unfinished".