Low and medium pile, yes — a good robot does well. Deep pile and shag, no. Robots are short and light, so on thick pile they lose traction, the brush can’t reach the base of the fiber, and the airflow chokes.

Where the line actually falls

Standard residential low-pile carpet and most area rugs are fine, and a good robot with carpet boost will lift a surprising amount out of them. Medium pile is where suction and brush design start to separate the good robots from the cheap ones — grit and dander get driven down into the pile and a weak machine just skates over the top.

Deep pile and shag is where I stop recommending robots entirely. Three things fail at once: the wheels lose grip and the robot bogs down, the roller can’t reach far enough into the fiber to agitate anything, and the pile chokes the airflow so the suction never reaches the debris. No pascal number on any box fixes that.

If it’s one rug, not the whole house

Draw a no-go zone around it in the app and move on. Every robot with mapping lets you do this in about thirty seconds, and it saves the robot from getting stranded on it, tangling the tassels, and calling for help.

If it’s wall-to-wall plush through the whole house, I’d rather tell you now than have you write me a frustrated email in two weeks. Put the money into a good upright instead. That’s the honest recommendation even though it costs me an affiliate sale.

Dad’s Take

Robots are short and light. On thick pile that’s a physics problem, not a shopping problem.