Robot Mops

Each robot required a bit of setup, but most were intuitive and easy to get up and running. We charged their batteries, slipped on the included sweeping or mopping pads or roller, filled their water tanks, and set the robots loose on our floors. (It’s worth noting that you can only use water and/or the manufacturer’s cleaning solution with each; all manufacturers state that using other household cleaners or vinegar will void the warranty.) Unlike robot vacuums, which whir loudly as they work, the mops were notably quiet, except for the occasional thump of the robot bumping into an obstacle. While it was deeply satisfying to watch the machines zoom about tidying up our floors, we quickly noticed a few limitations.

For starters, they’re not great at sweeping; at least for not large pieces of debris or food scraps. While the sweeping pads did pick up dust, dirt, hair, and the occasional carrot peel, they merely pushed around garlic skins and cereal pieces and abandoned them in corners of the room. We got the best results when we swept the floors with a broom before letting the robot mop the floor.

While they were more effective at mopping—our floors did look noticeably cleaner—most are definitely not a replacement for deep scrubbing. All the mops left bits of smoothie caked onto the floor, even after multiple passes, and one mop even had a hard time wiping up coffee or ketchup. Only one mop truly produced results that were similar to mopping by hand, but it had significant usability issues (more on that later). Instead, the results from most mops are similar to what you’d expect by using a wet sweeper such as a Swiffer. All the mops also come equipped with a spot-clean mode that allows the robot to deep clean a small area where you may have spilled something. While this setting was effective for fresh stains (such as muddy dog paw prints, as one test user discovered), it was also not much of a match for set-in stains. 

Lastly, as we discovered when testing robot vacuums, these motorized mops don’t clean places such as the corners of a room, the spaces where floors meet walls, and around furniture legs because of the limited sizes and shapes of their mopping pads, which are larger and less flexible than a traditional mop head. In the bathroom, most models struggled to fit into the tight spaces around and behind the toilet and pedestal sink. One robot was also too tall to fit under low-sitting furniture or even the toe kicks of a cabinet. We still had to clean all these spaces by hand.

So if you’re going to purchase a robot mop, it’s important to temper your expectations. These mops really function best when used daily as a way to maintain already clean floors. While they can lengthen the time between deep cleans, you’re still eventually going to need to break out a broom, mop, and bucket if you want truly sparkling floors.

That said, once we got the hang of using the robots as a supplement to our daily cleaning routine, we started to enjoy noticeably cleaner floors, at least with some of the robots. The most effective cleaning robots had two elements in common: a sophisticated cleaning system and a simple yet smart navigation system. 

The mops all cleaned in slightly different ways. The water tank of the least effective model slowly dripped water onto a mopping cloth that the machine essentially dragged across the floor. Two of the mops were equipped with spray nozzles that doused the areas to be cleaned with water and/or cleaner from their tanks before using a back-and-forth motion to wipe it up (both robots went over these sprayed areas three times). It took a bit longer for these machines to complete their cycles (it took up to an hour for the smaller of the two models to clean a 100-square-foot space), but their extended efforts resulted in fairly clean floors. By far, the most effective mopper was the ILIFE Shinebot, which has separate tanks for clean and dirty water and uses a roller, a scraper, and suction to douse the floor in cleaner, scrub the area, and take up the dirty water. It left our floors sparkling clean, but it had one glaring flaw: It lacked a smart navigation system.

It doesn’t really matter how well a robot cleans if it misses large swaths of the room or requires you to babysit it through the entire cleaning process, and here, the navigation system was key. The Shinebot uses a rudimentary navigation system that relies on pre-programmed cleaning patterns and sensors on the front bumpers that let it know when it has hit a wall or obstacle and needs to turn around. We frequently found that this model missed large swaths of the room, especially in rooms with many obstacles such as chair legs or furniture that triggered its bumper sensors and sent the robot off in another direction. It also regularly became trapped in a repetitive cycle, running into an obstacle and turning around only to travel back to the same obstacle over and over again. When this happened, we’d have to manually move the Shinebot to another part of the room.

The navigation system of another mop is contained in a special cube that you place on a countertop. The cube projects an invisible (to the human eye) pattern onto the ceiling. A sensor on the top of the robot reads the pattern and uses it to keep track of where it has and hasn’t been. While this model was more successful at covering the majority of a room, the cube frequently lost connection with the robot, and it took many tries to get it reconnected. The company’s tech support told us it can take up to 15 minutes for the robot to establish a connection with the cube each time you use it. They also noted that ceiling fans or cathedral ceilings can hinder the cube’s connection (though the rooms we tested the robot in had neither). Without its cube, this robot can only clean a very small, square area.

Our top two models, both from iRobot, rely on a more intelligent navigation system. A smaller, less expensive model uses a mapping system that iRobot calls iAdapt 2.0. The machine’s internal bumper sensors gather information to create a virtual map of the room. This resulted in wide coverage of the room. (Plus, this robot’s small size—just 7 inches wide and 3 inches high—enabled it to access hard-to-reach places such as under bookshelves and around the bathroom sink and toilet.) Unfortunately, this robot didn’t retain any of that information for future cleaning sessions; the map was deleted when the clean cycle was finished.

The top model from iRobot, the Braava jet m6 Robot Mop, takes room mapping a step further by using a navigation system called visual simultaneous localization and mapping (vSLAM). A camera mounted on the top of the robot helps it “see” the shape and size of objects in the room. From there, the robot plots the most effective course through the room and builds a storable map of the cleaning area. We found it methodical and efficient at cleaning, and its room coverage was the most thorough of all the robots we tried. This technology isn’t proprietary to iRobot; many new-generation robot vacuums use vSLAM or a similar smart mapping technology called light detection and ranging (LiDAR) that relies on lasers instead of a camera to build a detailed map of a room. (One of the reasons we liked our higher-rated robot vacuums was for their use of LiDAR technology.) However, the Braava was the only dedicated robot mop in our lineup with this smart mapping technology, and the result was efficient, accurate cleaning that required no manual intervention.

While efficient cleaning is one boon to smart mapping technology, the real advantage of the Braava’s intelligent mapping is that the mop gets smarter over time. When paired with iRobot’s free app, the robot creates an updated map of your home with every cleaning. After about five uses, you can use this map to name specific rooms and designate certain “no-go” areas. The result is a more customized experience; you can tell the robot to clean a specific room or to avoid cleaning a specific area. We found these features to be exceptionally accurate; when we used the app to instruct the Braava to clean the kitchen but stay away from the cat’s water bowl, the Braava followed the lines we drew on the map exactly. 

This app integration also allowed us to schedule cleanings or even use the Braava in conjunction with a smart assistant such as Amazon Echo or Google Home. “I felt like I was living in an episode of the Jetsons when I ordered it to clean while sitting on my couch,” reported one tester, who tried out this feature using their Amazon Echo Show. The app can also send firmware updates to the robot so that the mop can keep up with the latest advances in technology. Also, iRobot recently added a feature that allows the Braava to work in conjunction with some iRobot vacuums to vacuum and then mop with just the push of a button on the app. 

The iRobot Braava jet m6 Robot Mop is our standout choice for best robot mop. It was the most effective robot mop we tried, and it was also a pleasure to use. Its spray nozzle and triple-pass cleaning system made it effective at mopping up light messes, it automatically docked to recharge when it was done cleaning, and its smart mapping system provided the most accurate room coverage of all the robot mops we tested. However, at almost $500, it’s pricey—especially for a product that won’t completely replace mopping by hand. Like all the robot cleaners we’ve tried, it’s best used as a supplement to keep floors touched up between deeper cleanings; it didn’t sweep up bigger food scraps or scrub off dried-on food stains. The disposable cleaning pads cost a little over $1 each and need to be replaced after each session—which can add up to almost $400 per year if you plan on using the mop every day—though the company does offer a more sustainable reusable pad option for about $25 that you launder after each use.

If you don’t mind sacrificing some of the bells and whistles, we can also recommend a simpler, smaller model from iRobot: the Braava jet 240 Robot Mop, priced at about $175. It's a petite, nimble machine that works particularly well in small spaces such as bathrooms (it was the only mop we tested that could access the tight areas around sinks and toilets). It also nimbly weaved around chair legs in the kitchen, but it ran out of juice after cleaning a space that measured about 200 square feet and it doesn’t automatically dock itself to recharge, so it’s not ideal for bigger spaces. While it does work with the iRobot app, the features are very limited—you can instruct the robot to spot-clean its immediate area, but not much else.