The iRobot Roomba S9 is a premium robot vacuum in the manufacturer's high-end S Series lineup, above models like the iRobot Roomba j7 and iRobot Roomba i3. It performs quite well across a wide variety of surfaces, is very well-built, and maneuvers effectively on a wide range of surfaces. It also has outstanding battery life, allowing it to clean fairly large spaces without running out of charge. Unfortunately, it has quite a few parts that require regular maintenance or replacement. Still, if you're looking for a robot vacuum that can cope with a broad mix of different floor types, it's a good choice.
Our Verdict
The iRobot Roomba S9 is very good on bare floors. It clears pet hair and small debris such as rice without an issue, though it does experience a slight drop-off in performance with a full dirt compartment. It feels quite premium and has a long battery life that allows it to clean big rooms without running out of charge. Unfortunately, it has a lot of parts that need to be serviced regularly and has relatively high recurring costs.
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Excellent build quality.
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Fantastic battery performance.
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Amazing maneuverability.
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Clears debris effectively on bare floors.
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Strong overall performance on bare floors.
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High recurring costs.
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No hazard detection system
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Poor crack-cleaning capability.
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No mopping function.
The iRobot Roomba S9 is decent on low-pile carpet. It clears pet hair and larger material very easily, but it may take a couple of extra passes to clear away very fine debris. It's also well-built and has a very long battery life, which helps when cleaning big spaces. That said, it has quite a few parts that need to be replaced periodically but thankfully they're very easy to access.
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Excellent build quality.
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Fantastic battery performance.
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Easily clears away pet hair and larger debris.
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Amazing maneuverability.
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Struggles with fine debris on carpeted surfaces.
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High recurring costs.
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No hazard detection system
The iRobot Roomba S9 performs decently on high-pile carpet. It maneuvers effectively even on densely-woven carpet and does a good job of clearing various kinds of debris on this surface, though it struggles somewhat with finer material. Its surface detection system enables it to raise its brushroll on carpeted floors, so it shouldn't get stuck on thicker carpeting. However, it does incur somewhat high recurring costs.
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Excellent build quality.
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Fantastic battery performance.
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Easily clears away pet hair and larger debris.
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Amazing maneuverability.
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Struggles with fine debris on carpeted surfaces.
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High recurring costs.
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No hazard detection system
The iRobot Roomba S9 is an excellent choice for pet owners. It does a superb job of sucking up pet hair on a wide mix of surface types and feels quite well built. While the vacuum has quite a few parts that need to be serviced or replaced, you can remove its brushroll to detangle hair wraps. It also has a HEPA filter to trap allergens as you clean. Unfortunately, unlike some newer robot vacuums, it doesn't have a hazard detection system that would allow it to spot and react to obstacles like pet waste in real-time,
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Clears pet hair effectively.
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Amazing maneuverability.
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HEPA filter traps allergens as you clean.
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High recurring costs.
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No hazard detection system
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No mopping function.
The iRobot Roomba S9 is a robot vacuum that isn't suited for cleaning stairs.
The iRobot Roomba S9 is a robot vacuum that isn't designed to clean the inside of cars.
The iRobot Roomba S9 is a robot vacuum and isn't suitable for workshop cleaning.
- 7.7 Bare Floor
- 7.3 Low-Pile Carpet
- 7.2 High-Pile Carpet
- 5.7 Pets
- 5.6 Stairs
- 4.4 Cars
- 4.6 Workshop
- Updated Dec 01, 2022: We've updated the 'Differences Between Variants' section of this review to include the Roomba S9+ model.
- Updated Jul 29, 2022: Converted to Test Bench 1.1.
- Updated Jul 22, 2022: We've updated this review to Test Bench 1.0, which includes a broad range of new testing procedures to measure stain and water-clearing performance, suction power, crevice-cleaning performance, noise levels, and air filtration performance. We've also updated our debris and pet hair-pickup performance tests as well as our method of scoring user maintenance requirements and recurring cost.
- Updated Apr 25, 2022: Converted to Test Bench 1.0.
- Updated May 26, 2021: Corrected input error in 'Automation (Robot Vacuum)' section.
- Updated Oct 16, 2020: Review published.
- Updated Oct 08, 2020: Early access published.
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Differences Between Sizes And Variants
Another variant of the iRobot Roomba S9, referred to as the iRobot Roomba S9+, comes with an external dirt bin/charging station for automatic debris disposal. It's also currently the only other vacuum in iRobot's S Series model range. That said, both vacuums are mechanically identical with the sole exception of the S9+ having a slightly different internal dustbin, which features a debris disposal port covered by a rubber flap. Regardless, both models should deliver similar overall cleaning performance, though the inclusion of the auto-empty dock does reduce hands-on maintenance requirements.
You can buy a basic S9 and purchase the self-emptying base station later down the line, which also includes the redesigned internal dustbin. We tested the base variant with no external dirt compartment, and you can see its label here.
If someone comes across a differently-equipped iRobot S9, let us know in the discussions below so that we can update our review.
Compared To Other Vacuums
The iRobot Roomba S9 is a versatile robot vacuum. It cleans effectively on a wide mix of surfaces, feels quite sturdy, and offers exceptional battery performance. it also comes with a HEPA filter to trap allergens as it cleans. Unfortunately, it also has quite a few recurring costs and can be a little tricky to maintain, with quite a few parts that require regular servicing.
If you're looking for alternatives, take a look at our list of recommendations for the best robot vacuums, the best robot vacuums for pet hair, and the best robot vacuums for carpet.
The iRobot Roomba S9 and Roborock S7 each have their advantages, and one may suit you better than the other, depending on your needs. The iRobot has a bigger dirt compartment, maneuvers itself a little more easily, and clears far more debris on low and high-pile carpet. It also takes much less time to recharge, though the Roborock has longer battery life. The iRobot's HEPA filter does a much better job of sealing in allergens as well. The Roborock is also a little less demanding in terms of regular maintenance, incurs lower recurring costs, and performs slightly better overall on bare floors. It also comes with a mopping attachment that's impressively well-suited to tackling dried-on stains. Its LIDAR mapping system also makes it a better option for cleaning in dark rooms.
The iRobot Roomba S9 is better overall than the iRobot Roomba i7. The S9 performs better on all surface types, feels better-built, has lower recurring costs, and has a maximum battery life more than twice as long as the i7. The i7 does come with an automatic dirt disposal feature. This effectively gives it a much larger dirt compartment via an external dirt bin that it can return to when full. However, it should be noted that the same option is available for the S9 at an added cost.
The Roborock S7 MaxV is more advanced than the iRobot Roomba S9. Both are high-end robot vacuums, but the Roborock has a LIDAR mapping sensor that allows it to easily navigate in the dark, as well as twin front-facing cameras that let it spot and avoid hazards in real-time. The Roborock also has an ultrasonic mopping function to scrub away dried-on dirt. However, the iRobot could be a better option for some pet owners. Its HEPA filter is more effective in sealing in fine allergens like pet dander, and it does a significantly better job cleaning up pet hair on carpeting. While you can bundle both with self-emptying stations, the Roborock's top trim docking station is more advanced, as it not only empties its dustbin but also cleans its mopping pads and refills its water tank. However, it's very pricey.
The iRobot Roomba S9 is better than the iRobot Roomba j7. The S9 incurs lower recurring costs, charges faster, has an automatic suction power adjustment feature, and performs better on all surface types. Like the j7, it can also be purchased with an external dustbin and a corresponding self-emptying capability at an additional cost. Meanwhile, the j7 has its unique hazard identification feature and weighs notably less.
The iRobot Roomba S9 is a better robot vacuum than the Ecovacs DEEBOT OZMO T8 AIVI. The iRobot is easier to maintain and offers a better cleaning performance on all surface types. However, the Ecovacs has fewer recurring costs and has a mop attachment, although we don't currently test this feature.
The iRobot Roomba S9 is better than the iRobot Roomba i3. The S9 is better-built, incurs fewer recurring costs, has a longer battery life, maneuvers itself more effectively, and performs better on all surface types. Meanwhile, the i3 has a self-emptying function, though it's worth noting that this feature is also available for the S9 at an additional cost.
The iRobot Roomba S9 is better than the iRobot Roomba i4. The S9 is better-built, easier to maintain, has a larger dustbin, and delivers superior performance on bare floors as well as low and high-pile carpeting. It also does a better job of maneuvering itself around obstacles.
The iRobot Roomba S9 is better than the iRobot Roomba 981. The S9 feels better-built, has a longer battery life, charges faster, delivers better performance on low and high-pile carpet, and has a more advanced mapping system that stores a permanent map of its coverage area, allowing you to set up virtual boundary lines or schedule cleaning sessions for specific rooms. Meanwhile, the 981 incurs lower recurring costs.
The iRobot Roomba S9 is better than the Shark AI Robot. The iRobot is better-built, has fewer parts requiring regular maintenance, charges much faster, has an automatic surface detection system, maneuvers itself more effectively, and clears more debris on bare floors and low and high-pile carpet. Conversely, the Shark incurs lower recurring costs and has a longer maximum battery life.
The iRobot Roomba S9 is better than the eufy RoboVac X8, though the eufy is still a solid option if you want something a little more affordable. The iRobot feels better-built, is easier to maintain, has a larger dustbin, and can automatically change its brushroll height to match different surfaces. It also does a better job of maneuvering itself and clears away more debris on carpeted surfaces. That being said, the eufy does a slightly better job of sucking up debris in crevices and incurs lower recurring costs.
The iRobot Roomba S9 is better than the iRobot Roomba 694. The premium-priced S9 feels better-built, has an onboard HEPA filter, uses a larger dustbin, has a far more advanced suit of automation capabilities, does a better job of maneuvering itself, and performs better on all surfaces. However, the 694 incurs lower recurring costs.
The iRobot Roomba S9 is better than the Shark IQ Robot. The iRobot is better-built, easier to maintain, charges faster while offering similar battery performance, and delivers much stronger performance across a variety of surface types. It also has a far more advanced suite of automation features, as it allows you to configure its coverage map with no-go zones or schedule cleaning times for specific rooms.
The Roborock S6 and iRobot Roomba S9 are somewhat evenly matched, but for different reasons. The Roborock is slightly easier to maintain, incurs marginally lower recurring costs, has a longer overall battery life, and is more effective with clearing large debris, like cereal, on bare floors. It also has a mop attachment to deal with wet messes, but we don't test that particular feature. Conversely, the iRobot performs better on carpeted surfaces, has a slightly larger dirt compartment, and charges almost twice as fast.
The iRobot Roomba S9 and yeedi vac station each have their own advantages, so one may suit you better than the other depending on your needs. The iRobot is better-built, incurs lower recurring costs, is equipped with an allergen-trapping HEPA filter, doesn't struggle with bulky debris, and performs considerably better on low-pile carpet. It also charges considerably faster than the yeedi. Meanwhile, the yeedi's self-emptying feature reduces hands-on maintenance requirements and gives it a much larger effective debris capacity. The yeedi also delivers better performance high-pile carpet. It's also equipped with a mopping attachment for clearing messes on bare floors, but it takes quite a while to deal with dried-on debris.
The iRobot Roomba S9 and Neato D8 each have their strengths, so one may suit you better depending on your exact needs. The iRobot feels better-built, has a longer maximum runtime, delivers better performance on low-pile carpet, and maneuvers itself more effectively. That said, the Neato clears more debris on bare floors and high-pile carpet, is less demanding in terms of maintenance, and is notably lighter in weight.
The Neato Botvac D7 and the iRobot Roomba S9 have different strengths. The Neato is much easier to maintain, has a considerably longer minimum battery life, and performs better on bare floors. The Roomba feels better-built, clears more debris on both low and high-pile carpet, and can maneuver around obstructions like electrical cords more easily.
The iRobot Roomba S9 is a better robot vacuum than the Roborock S4 Max. The iRobot is better-built, uses a larger internal dustbin, and charges in little under a third of the time as the Roborock. The Roborock also delivers superior performance on all surface types.
The iRobot Roomba S9 is a significantly better robot vacuum than the ONSON GOOVI F007 Robot Vacuum. The iRobot feels better-built, is easier to maintain, and recharges in less time. It also offers significantly better performance on all surface types and has better maneuverability. However, the ONSON is much more portable as it weighs less.
The iRobot Roomba S9 and the Roborock S6 MaxV have different strengths, and you may prefer either one depending on your needs. The iRobot delivers a much better cleaning performance on bare floors as well as low and high-pile carpets. It uses a sensor to detect areas that need extra cleaning and can automatically adjust the height of its brushroll. However, the S6 Max has better automation. It has a unique 'ReactiveAI' feature intended to detect obstacles and allow the vacuum to avoid them.
The iRobot Roomba S9 is a better overall robot vacuum than the Roborock S5. The Roomba is better-built, charges faster, and performs much better on carpeted floors. That said, the Roborock is easier to maintain, has lower recurring costs as well as longer minimum battery life, and performs slightly better on bare floors. I
The iRobot Roomba S9 is a better robot vacuum than the Narwal T10. The iRobot has a much larger internal dustbin, can maneuver around or over obstacles like rugs more effectively, and clears more debris on almost all surface types. However, the Narwal does have a mopping system for dealing with messes on bare floors. Its LIDAR mapping system also allows it to navigate far more easily than the iRobot in the dark.
Test Results
The iRobot S9 is very well-built. Its D-shaped body, similar in profile to that of the Neato Botvac D7, is made of high-grade plastic, accented with a matte-finish copper lid. Its dirt compartment feels mostly sturdy, though its bottom does feel somewhat flimsy and could potentially break if it's dropped. It comes out of the box ready to use, with no assembly required except for setting up its dock station.
This vacuum is pretty easy to maintain.
- Dirt compartment: The dirt compartment is found under the copper bin lid. It features a built-in carrying handle and a release button to open the bottom of the compartment and drop any stored debris. Aside from releasing debris, you can clean it by tapping it against the side of a garbage bin or washing under water. You need to remove the filter before doing so since it isn't washable.
- Filter: The filter is located inside the vacuum's dirt compartment. You can tap it against your garbage bin to dislodge any stuck-on debris, though this component isn't washable and shouldn't be cleaned with water. Like most other parts here, it needs to be cleaned once or twice a month, depending on if you're a pet owner.
- Brushrolls: The brushrolls are accessed by removing the brush guard under the vacuum. You can clear stuck debris or hair wraps by hand once or twice a month, depending on use. It can be a little hard to reinsert the brushroll since it needs to be precisely aligned.
- Side brush: You need a screwdriver to remove the side brush. You should clean it by removing tangled hairs once or twice a month, depending on whether or not you have pets.
- Wheel: You can pull the wheel out of its cavity and push it out of the socket to clear any tangled hair or stuck-on debris. It should be cleaned every two weeks.
Any part that's washed in water should dry for 24 hours before use again.
The iRobot Roomba S9 has quite a few sources of recurring costs that can add up over time.
- HEPA filter: The HEPA filter needs to be replaced every two months.
- Rubber brushrolls: The rubber multi-surface brushrolls should be replaced every 12 months.
- Side brush: The side brush can be removed and replaced every three months.
- Rear caster wheel: The wheel should be removed and replaced every 12 months.
If you don't want to buy these parts individually, the manufacturer sells a 'Replenishment Kit' that includes three side brushes, multi-floor rubber brushrolls, and three HEPA filters. Take a look at the Roborock S7 if you're looking for a premium robot vacuum with fewer recurring costs.
This vacuum has outstanding storage capabilities. It's quite small and comes with a low-profile charging station with a nook to store any excess length of power cable.
This vacuum has an okay dirt compartment. It's fairly sturdy, though its bottom feels like it could potentially break if dropped. It features sensors to let you know once it's full, either via an in-app notification or with the indicator light on top of the vacuum turning from white to solid red.
- iRobot Roomba S9 robot vacuum
- Charging dock
- Charging cable
- 2x HEPA filter
- 2x multi-surface rubber brushrolls with bearings
- 2x side brush (one already inside the vacuum)
- Dirt compartment
- User guide
This vacuum's range is limited only by its remaining battery life, though it can't climb up or down staircases.
The iRobot S9 isn't especially portable. It's heavier than alternatives like the iRobot Roomba j7 and lacks a carrying handle to help you carry it from room to room or up and down flights of stairs.
The iRobot Roomba S9 has remarkable battery performance. It automatically adjusts to different surface types, though you can manually adjust its power setting through three levels: 'Lower', 'Balanced', which is the default, and 'Exceptional'. Even in its strongest suction mode, it supplies just under 50 minutes of continuous runtime. Used more conservatively, its continuous battery life extends to over two and a half hours, which is fantastic. The LED light on top of its body notifies you of the current charge status, with the light going from white to red when its battery level is low.
This robot vacuum has a couple of different quality of life features. It features a dirt sensor to detect high concentrations of debris and focus its power in those areas. It also has three power levels; the high-power 'Custom + Exceptional Cleaning Power', the default 'Detailed Clean' mode, and the energy-efficient 'Quiet Clean' mode. It also has an auto-adjusting vacuum head that can change height to suit different floor types.
The iRobot S9 comes with two multi-floor rubber brushrolls. Unlike the more common three-armed side brush used by other vacuums in the manufacturer's lineup such as the iRobot Roomba i7, it comes with a five-armed side brush.
The iRobot S9's performance on bare floors is superb. It clears away small debris like rice and bulkier debris like cereal without an issue, with no major drop in suction power as the dirt compartment fills up.
The iRobot S9 is okay on low-pile carpet. It sucks up larger material, like sand, with very little trouble. However, it has a very hard time dealing with finer debris like baking soda on this surface type, and will probably require a couple of extra passes to remove all of it.
The iRobot S9 delivers good performance on high-pile carpet. Unlike the ONSON GOOVI F007 Robot Vacuum, the S9 easily clears away larger debris like sand. However, it'll probably require a couple of extra passes to deal with finer debris like baking soda.
The iRobot Roomba S9 does a fantastic job of dealing with pet hair across a variety of surfaces, ranging from bare floors to low and high-pile carpeting.
The iRobot Roomba S9's real-world suction power is relatively strong for a robot vacuum, exceeding that of the iRobot Roomba i3. That said, it isn't as potent as newer flagships like the Roborock S7 MaxV. In any case, its suction inlet is positioned too high above the contact surface to generate a tight seal on bare surfaces, resulting in low suction power measurements.
The iRobot Roomba S9 is impressively quiet. The sound of it running shouldn't be especially disruptive if you have it running in an adjacent room with the door closed, but you'll have to raise your voice somewhat when speaking to somebody in the same room as the vacuum while it's operating.
This robot vacuum has amazing maneuverability. Like the iRobot Roomba i7, it uses the iAdapt 3.0 navigation system to create an efficient cleaning route and maneuver around obstructions. It also goes over spots that it deems in need of additional cleaning. The vacuum itself isn't very tall, so it shouldn't get stuck under tables or couches. While it can get stuck on rug tassels, it doesn't get tangled on obstructions like power cables, though it may push them around.
The iRobot Roomba S9 is effective at sealing in fine allergens. It has an onboard HEPA filter and does a significantly better job of sealing in particles compared to other robot vacuums like the Roborock S7.
The iRobot Roomba S9 struggles with cleaning debris in cracks and crevices. It can't generate a tight enough seal against the contact surface to draw out debris in deeper cracks and crevices, and its side brush tends to scatter debris around instead of directing it towards its brushrolls. Running it in its 'Exceptional Cleaning Power' mode does help it clear a little more debris in deep and medium-depth cracks, but not by much.
The iRobot Roomba S9 does a terrible job of dealing with stains. Unlike other high-end models like the Roborock S7 MaxV, it doesn't have a mopping attachment that would allow it to scrub away dried-on stains.
The iRobot Roomba S9's automation features are passable. During setup with the iRobot Home companion app, it uses its navigation system to create a virtual map of the layout of your home. One convenience is that if the vacuum runs out of battery while cleaning a room, it will remember the incomplete job and return once it's been recharged.
You can purchase a charging station/dirt bin separately or as part of a more expensive S9 variant, called the S9 Plus, which gives the vacuum a standalone dirt compartment built into its charging dock to automatically empty itself of debris and continue cleaning.
The iRobot HOME companion app is great. It allows you to schedule cleaning times for individual rooms and set up virtual boundary markers. The app also shows your previous cleaning history and remaining battery life. It's also fully compatible with Amazon Alexa and Google Home devices, so you make specific inputs with voice commands.