Is the Wii U a Handheld System? No—Home Console with GamePad

No. The Wii U is a home console (like Xbox 360/PS3) that connects to a TV.

Its unique Wii U GamePad has a built-in screen for off-TV play, but it's not a standalone handheld—it requires the console base unit.

The Nintendo Switch succeeded the Wii U as a true hybrid (home + handheld).