Nikon claims that "the Z8 condenses the advanced functionality and performance of the flagship Nikon Z9 into a compact and lightweight body while also maintaining superior robustness and reliability." The Z8's body is 15% smaller than the well-liked D850 and about 30% smaller than the Z9's.

The 45.7MP stacked CMOS sensor and EXPEED 7 image-processing engine featured in the Z9 are the foundations of the Z8 as well. It also carries over Nikon's "blackout-free" viewfinder, completely electronic shutter, and 3D-tracking autofocus system built on deep learning technology. Similar to the Z9, the new model can shoot 20 frames per second in RAW, 30 frames per second in full resolution, and 60 frames per second in cropped (DX-format) JPEGs. Pre-release capture, another feature of the Z8, allows the buffer to take pictures even before the shutter is fully pushed.

Videos may be captured in up to 4K/120p from (subsampled) 8.3K capture as well as 8K/60p in Nikon's proprietary, compressed 12-bit RAW format, N-RAW, both of which the Z9 later acquired via a firmware update. Additionally, the Z8 can record 12-bit RAW video in ProRes RAW 4K/60p.
One CFexpress port and an SD card slot are available on the Z8.