iRobot Roomba Combo j9+ – as good as a robot vacuum gets

The iRobot Roomba Combo j9+ robot vacuum and mop is the best I've ever tested.

An iRobot Roomba j9+ Combo Robot Vacuum and Mop
(Image credit: iRobot)
Homes & Gardens Verdict

This is the best robot vacuum I've tested, with an excellent app, good performance on carpet, and an excellent mop for hard floors. However, it's very expensive, the clean base is very loud, and far from perfect with bigger crumbs.

Reasons to buy
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    Good suction

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    Great on fine dirt on hard floors

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    Good on hair

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    Easy automation

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    Simple app

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    Relatively quiet when vacuuming

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    Great mop

Reasons to avoid
  • -

    Incredibly loud self-emptying

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    Not a perfect clean

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    Shape means it struggles to clean circular objects

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I was a little skeptical when we went to the press briefing for the iRobot Roomba Combo j9+. I've tested a fair few robot vacuums in my time and I've never quite been convinced. They're often ugly, expensive, don't clean particularly well, and rarely as 'automatic' as the marketing materials claim. 

However the j9+ aims to crack two out of three of these, and I was very intrigued as the meeting went on. Where lots of robot vacuums have ugly housing, the charging and cleaning base for this vacuum is topped with wood, so it can be used as a side table.

Unlike most other robot vacuums and mops, the mop is totally automatic, with the robot switching functions and wetting a mop pad by itself. It claimed new levels of suction, scrubbing on hard floors, and a handy sweeping arm that knocks dirt into its path. However, at full price, it will set you back $1399. 

This all had me very curious, and I was lucky enough to get a sample to test over the past few weeks. The long and the short of it is that this is an exceptional robot vacuum with some quirks. If you're looking for a robot vacuum, it doesn't get any better than this – just don't expect any miracles. 


An iRobot Roomba Combo j9+ Robot Vacuum and Mop on a white background

(Image credit: iRobot)
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Dimensions17.2" x 18.1" x 17.5"
Noise50 dBa
Dustbin capacity0.26 gallons
Clean base dimensions15.8" x 12.2" x 13.3"

Who would it suit?

This robot suits those in small homes and apartments with mixed flooring. It does a largely great job on floor types and types of dirt, but it's very expensive for what it is, so it won't work if you're on a budget. 


Unboxing the iRobot Roomba j9+ Combo

(Image credit: Future)

Setting up this robot was the best unboxing experience I've had with a robot vacuum, but it still took a while before it was running. It was a little tricky to wrangle the box upstairs to my apartment, but that's also typical for a vacuum of this size. 

Once upstairs, I cleared a space for it and got to work. One of my criticisms is that you need a lot of clearance for the clean base. It needs four feet to the left and one foot to the right. It makes sense - the robot needs to be able to see where it's going - but it's a little frustrating. There's a corner of my living room that's the perfect size for this vacuum, but with the way the walls line up I couldn't place the clean base there. Instead, it's slightly awkwardly in the middle of the wall. 

Once everything was in place, set up took me about an hour. Aside from attaching the mop and putting the robot in its base, there's actually very little to do. The only big thing was filling up the water tank for the mop. But while the instructions were clear, most of my time was taken up with setting up the app. Again, this is very simple, but there's a lot of hoops to jump through as you have to sign up for an iRobot account. It feels like a way to get my email rather than having any particular benefits, and a decent chunk of the app is dedicated to selling other iRobot products, which is frustrating. 

The j9+ then ran a cleaning and mapping run for 39 minutes. The map didn't look quite right, so I then sent it out on another mapping run for 9 minutes. All in all, very easy to set up, if a little long.

What is it like to use?

The iRobot Roomba Combo j9+ Robot Vacuum and Mop in my apartment

(Image credit: Future)

Over the weeks that I've been using this vacuum I've found that the dirt detective function is really useful. It can tell which parts of your home pick up the most dirt; in our case, the entryway. The robot will then give that area special attention, and the map will tell you how long since it's been cleaned and how dirty it's likely to be. You can contrast that with the spots over by the window where there's rarely dirt, or the hallways, which doesn't need as much cleaning.

I've also noticed the robot becoming more and more efficient. The vacuuming runs and less and less erratic. At the start of using it I found the robot moved at what seemed like random as it vacuumed. Now it takes simple, back-and-forth straight lines across the room. That's on top of the keep out-zones, which stop the robot going into areas it shouldn't. I have one for directly under the couch, where there's an extension lead that might gum up the brush bar, and on the past weekend I set one for the Christmas tree. The robot will totally avoid these and it's excellent peace of mind.

The app of the iRobot Roomba j9+ Combo

(Image credit: Future)

The app is fantastic. It's a little slow sometimes and a little glitchy, but largely easy to use. The map is clear and accurate and it's a simple, user-friendly interface that anyone can use. You don't need to be a tech genius for this to work. 

Sitting at my desk, it's fairly quiet; it averages at about 50db, which is pretty good for a vacuum, but you won't be able to listen to music or watch TV as it runs. However, by far the worst feature of this vacuum is the noise of the clean base as it empties the vacuum. The automatic dirt removal is fantastic, but when it sucks out the waste the noise gets up to 80db. I promise I'm not exaggerating: it sounds like a jet is taking off. It's loud enough that you can't hear yourself talk under it, and because the base is on the floor and against a shared wall, I'm certain it's disturbing the neighbors.

Test 1: Cereal

For its performance on carpet, I'd say it's 98% of the way there. It's largely effective and the apartment always looks and  I've set it running again as I write just in case there's anything I've missed over the past few weeks and I just watched it knock cereal into its path and it easily picked it up. Not only was it good on carpet, but it was good on an area rug, too. We have a rug that sheds a lot and this does an excellent job of getting rid of all the fluff.

Testing cereal on a carpet with the iRobot Roomba j9+ Combo

(Image credit: Future)

However, like other robot vacuums, there is almost always something big that it misses; a scrap of a leaf, or a hair, or a crumb. It leaves behind the kind of dirt you would immediately spot and grab if you were vacuuming manually. In this case, a couple pieces of cereal in the kitchen and the living room, as well as some paper from a notebook. To be fair, it was skirting close to a keep-out zone, but you'd still expect the vacuum to clean right to that edge The overall performance is fantastic and it gets most of the dirt, but when you look down and see a big a piece of lint, it doesn't feel that clean. If I know I have people coming over, I still manually vacuum the carpet with a cheap cordless, because I can do a faster, better job. It slightly defeats the point. As robots go, it does an excellent job, but it's not perfect.

Test 2: flour and sugar

Before and after, testing flour and sugar with the iRobot Roomba j9+ Combo

(Image credit: Future)

We test with flour and sugar on carpet and hard floors as a proxy for dust and dead skin. This robot easily took care of it, clearing a path straight through the sugar and flour, which was most visible on the hard floor in the kitchen. Unlike other robots, none of the dirt stuck to the wheels, so it wasn't tracked through the rest of the house. There's more on this below but it was especially great that this vacuum could mop afterwards, too, as there was no left-over stickiness to the floor. It passed this test with flying colors. 

Test 3: hair

The rollers on the iRobot Roomba j9+ Combo

(Image credit: Future)

This vacuum is one of the best I've ever tested for hair wrap. My partner has long hair and our usual cordless vacuum has pretty poor hair wrap, so I'm always cutting itout of the rollers. The Combo j9+, however, has two bumpy, silicone rollers that never gum up with hair. It always pulls hair out of the carpet and does a much, much better job that even some of the bestbest vacuums for pet hair.

Test 4: The mop

This robot also has its own mop. I love this function, as unlike other robot vacuums you don't need to swap any attachments. The mop sits on the back of the robot and automatically flips out for cleaning. It's one of the most ingenious designs I've seen, as one of my biggest complaints with other vacuums is that you have to swap out the attachments and fill up the water tank yourself, which defeats the point of a robot mop. Another great design point is that on other robots, the mop sits underneath the vacuum at all times, which then drags dirty water around the house. On this vacuum, it will never drag across the carpet, so everything is always dry. 

It definitely makes a huge difference when this mops. I know I should do it more often but I can rarely be bothered to mop the hard floor in my kitchen. This robot does it every time it runs and the floor is shinier and cleaner for it. I also love that this vacuum can scrub. Unlike other robot mops, it can scrub at particularly hard dirt and areas it knows gets a lot of traffic. That means hard food stains come up pretty easily. 

However, it struggles with getting into corners, which is a little frustrating, and here is where I found the biggest issue with its shape. To be fair to iRobot, that's not something that could be easily fixed, but it struggles to clean around our round trash can. A circle bumping into a circle means that is rarely gets up those small food stains that accumulate as you throw out waste.

Cleaning, storage, and maintenance

The view inside the the clean base of the iRobot Roomba j9+ Combo

(Image credit: Future)

Cleaning this robot vacuum is very simple. After more than a month of using this vacuum I haven't had to empty it or refill the water tank once. All the accessories, like a spare mop and the instructions, fit into the handy door in the clean base, so everything is compact and neat. You have to remember to dust the clean base and vacuum occasionally, but that's no different from having a coffee table, 

How does it rate online?

A few reviewers found that the robot gets stuck, which happened to me once when I tried to see how it would clean without me in the apartment to supervise. Most reviews found that it largely does a good job at cleaning and that the mop is a particular highlight. One reviewer on Amazon said it didn't do a great job with pet hair, which I find surprising as I thought it was excellent with hair. Some users also found that it takes a while to clean larger homes; it has a runtime of about 60 minutes before needing a charge, so you may find the runtime on jobs increasing if the robot needs to charge midway through. 

How does it compare?

This is the best robot vacuum you can buy. The suction is as as or better than most robots we've tested and two features really stand out. The clean base isn't an innovation, but disguising it - or at least attempting to disguise it - as a low coffee table makes this a much more attractive appliance than most. 

The other is the automatic mopping. For example, take the Eufy X8 Pro. It's a combo vacuum and mop just like this. However, on the Eufy you have to swap out the mops yourself, and even wet the floor before hand, at which point you might as well do the job yourself. It's a similar story with the Shark AI Ultra 2-in-1.

This is better than other Roomba products, too. It's less aggressive than the s9+, which we found did a great job cleaning, but often bumped into furniture, and a better job than its predecessor, the iRobot Roomba j7+. 

Alex David
Head of eCommerce

As Head of eCommerce, Alex makes sure our readers find the right information to help them make the best purchase. After graduating from Cambridge University, Alex got his start in reviewing at the iconic Good Housekeeping Institute, testing a wide range of household products and appliances. He then moved to BBC Gardeners’ World Magazine, assessing gardening tools, machinery, and wildlife products. Helping people find true quality and genuine value is a real passion.