FAMIVAC R10

Suction in pascal, as the maker measures it. More pascal helps on carpet, but it says little about how well the robot picks grit off a hard floor.

A brush that guides hair to the side instead of letting it wind around the shaft. It saves the cutting work in homes with long hair or pets.

The floors the maker says the robot cleans well: hard floor, wood, low-pile or high-pile carpet. High pile is where most robots struggle.

The filter the exhaust air passes through. A HEPA filter holds back fine dust and pollen, which counts if someone at home has an allergy.

How much clean water the robot carries. It sets how long it mops before a refill, which a dock does by itself.

How the robot maps your home and follows that map. Lidar measures with a laser and works in the dark, a camera looks along and recognises more.

Sensors under the robot that see a drop, so it stops at the top of a staircase instead of falling down it.

How tall the robot is. It decides whether it fits under your sofa, bed or cabinet.

What the robot weighs. It counts most if you carry it up a staircase every day.

How much dust the robot holds before you empty it. It matters less with an auto-empty dock, which empties the bin after every run.

The noise in decibels, in the setting its source names: makers mostly give the standard setting, shops often the highest. 65 dB is like a vacuum at half power, 55 dB like a conversation.

The capacity of the battery. It hints at the runtime, but how much the robot draws counts just as much.

How long the robot cleans on one charge, at its quietest setting. After that it recharges and carries on where it stopped.

How long an empty battery takes to charge fully in the dock.

Which voice assistants the robot works with, such as Google Assistant or Alexa.