Ecovacs DEEBOT X2 Omni

It empties into a 3 L bag and holds 4 L of clean and 3.5 L of dirty water, so most homes go weeks between refills.

The robot is 3.7 inches tall, so it slides under most sofas and cabinets, though very low furniture may be tight.

It clears obstacles up to 22 mm, so it handles standard door sills but may stop at taller thresholds.

The mop offers 50 moisture levels, so you can fine-tune from a light damp pass to a wetter scrub.