On carpet, suction and carpet-boost are the whole ballgame — mopping isn’t
A carpet-first home is the one case where suction really is the headline spec — the opposite of hard floors. Dirt, dust and pet hair sink into the pile, and it takes genuine airflow plus an agitating roller to lift it out instead of skating over the top. Two features matter most here: carpet auto-boost (the robot senses it's crossed onto a rug and ramps suction to max automatically), and a stiff, well-sealed main brush that reaches the fibers — a flimsy roller with a loose air path wastes whatever Pa the spec sheet claims. The flip side: on a mostly-carpet home a mop is close to useless (the robot just lifts it out of the way), so you can often skip the expensive mop tier entirely and put the money into a stronger vacuum — a vacuum-only unit like the eufy L60 or Shark can be the better value here. The tool below is pre-weighted toward max suction for carpet; drag the mop slider to zero if your home is all rugs, and the value ranking re-sorts instantly. Every slider is yours.
The self-empty dock is what actually makes it "set and forget"
The single biggest quality-of-life jump isn't suction — it's the auto-empty dock. Without one, you empty a tiny onboard bin every day or two. With one, the robot returns to a base that vacuums its own bin into a large bag you change every ~1–2 months. The iRobot Roomba Combo j9+ here goes ~60 days between bag changes; the eufy L60 and Shark ~45 days. The all-in-one "Omni" docks (Roborock, Dreame, ECOVACS, Narwal) go further — they also wash and dry the mop pads and refill the clean-water tank, which is the difference between a robot that mops and a robot that mops without you rinsing gross pads. That's why "hands-off" weights dock capacity heavily.
Mopping: a wet rag vs. an actual mop
"Mopping" spans a huge range, so we score it as a 0–3 tier. Tier 1 is a drag-cloth — a damp pad dragged behind the robot; it wipes light dust, not much more. Tier 2 is a vibrating or pressure mop that scrubs a bit. Tier 3 is a self-washing, auto-lifting dual-spin mop that applies downward pressure, spins, lifts over carpet so it doesn't soak your rugs, and washes itself at the dock — genuinely useful on tile and sealed hardwood. If your home is mostly hard floors, weight this; if it's mostly carpet, a vacuum-only unit (eufy L60, Shark) may be the better value.
Navigation: why the cheap ones bump around
Navigation (also 0–3 here) is the gap between a robot that maps your home and cleans in tidy rows and one that ping-pongs randomly. Tier 2 is LiDAR SLAM — a spinning laser that builds an accurate map, cleans efficiently, and lets you set no-go zones. Tier 3 adds AI obstacle avoidance (dToF + cameras) that dodges cords, socks, and pet accidents instead of dragging them across your floor. If you've got a cluttered home or a puppy, tier 3 earns its premium; a tidy open floor plan does fine on LiDAR alone.
Why we don't just name a winner
"Best robot vacuum" depends entirely on your floors, your pets, and your tolerance for maintenance. A carpeted home with a shedding dog wants max suction; an all-tile home wants the tier-3 self-washing mop; the person who wants to forget it exists wants the biggest auto-empty dock. One name buries all of that — the Value Score keeps it in your hands, formula in the open right above. Compare Roborock vs Dreame vs eufy vs iRobot vs ECOVACS vs Narwal vs Shark by the specs that matter to you.
The specs, briefly
Suction (Pa) = airflow/pull; higher = better on carpet, but not third-party standardized (approx). Runtime = rated minutes per charge; bigger homes need more (most auto-resume after recharging). Empty (days) = how long the dock goes between manual emptying. Mop (0–3) = none → self-washing dual-spin. Nav (0–3) = random → LiDAR + AI obstacle avoidance. Noise = operating dBA (lower is better — scored inverted).
Specs verified Aug 2026 against manufacturer spec sheets. Suction (Pa) and operating noise (dBA) are not standardized across brands — each measures its own way — so treat them as approximate and weight accordingly; they're the softest fields here. Mopping and navigation are encoded as 0–3 capability tiers from each unit's published mechanism (self-washing dual-spin mop, LiDAR + AI obstacle avoidance, etc.). Prices are approximate street prices. Some links may be affiliate; that never changes the Value Score — the math runs on published specs, not payouts.