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iRobot Roomba S9 Vacuum Review

Tested using Methodology v0.8
Reviewed Oct 16, 2020 at 09:19 am
iRobot Roomba S9 Picture
7.8
Bare Floor
7.6
Low-Pile Carpet
7.3
High-Pile Carpet
8.8
Pets
5.8
Stairs
5.6
Cars
Vacuum Type
Robot
Bagless
Yes
Cordless
Yes
Anti-Allergy Filter (HEPA)
Yes

The iRobot Roomba S9 is a premium robot vacuum in the manufacturer's high-end S Series lineup. 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

7.8 Bare Floor

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.

Pros
  • Excellent build quality.
  • Fantastic battery performance.
  • Amazing maneuverability.
  • Clears debris effectively on bare floors.
Cons
  • Bulky design lacks a carrying handle.
  • High recurring costs.
  • Demanding maintenance requirements.
7.6 Low-Pile Carpet

The iRobot Roomba S9 is good on low-pile carpet. It clears pet hair and coarse material like sand very easily, but it may take a couple of extra passes to clear finer debris, like baking soda. 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 recurring costs and can be a little finicky to maintain.

Pros
  • Excellent build quality.
  • Fantastic battery performance.
  • Good performance on carpeted surfaces.
  • Amazing maneuverability.
Cons
  • Bulky design lacks a carrying handle.
  • High recurring costs.
  • Demanding maintenance requirements.
7.3 High-Pile Carpet

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 messes like baking soda spills. However, it can be quite pricey to maintain and has quite a few parts that you need to maintain regularly.

Pros
  • Excellent build quality.
  • Fantastic battery performance.
  • Good performance on carpeted surfaces.
Cons
  • Bulky design lacks a carrying handle.
  • High recurring costs.
  • Demanding maintenance requirements.
8.8 Pets

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.

Pros
  • Excellent build quality.
  • Clears pet hair effectively.
  • HEPA filter traps allergens as you clean.
Cons
  • High recurring costs.
  • Demanding maintenance requirements.
5.8 Stairs

The iRobot Roomba S9 is a robot vacuum that isn't suited for cleaning stairs.

5.6 Cars

The iRobot Roomba S9 is a robot vacuum that isn't designed to clean the inside of cars.

  • 7.8 Bare Floor
  • 7.6 Low-Pile Carpet
  • 7.3 High-Pile Carpet
  • 8.8 Pets
  • 5.8 Stairs
  • 5.6 Cars

Test Results

perceptual testing image
Design
8.5
Design
Build Quality

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.

5.0
Design
User Maintenance

This vacuum is quite demanding in terms of maintenance, with quite a few parts that need to be serviced regularly. Thankfully, they're quite easy to access.

  • 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.

4.0
Design
Recurring Cost
Bag Part Number
No bag
Filter Part Number
4643682
HEPA Filter Part Number
4643682

This vacuum 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.

9.0
Design
Storing
Height
4.33 in (11.0 cm)
Width
12.20 in (31.0 cm)
Depth
14.57 in (37.0 cm)
Cord Storing/Management
Not Needed
On-Board Tool Storage
Not needed
Vacuum Rack/Station
Yes

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.

6.9
Design
Dirt Compartment
Dirt Compartment Volume
0.13 gal (0.50 L)
Full Dirt Compartment Indicator
Yes
Bag Included
No Bag Needed

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.

Design
In The Box

  • 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

10
Design
Range
Cord Length
N/A
Hose Length
N/A

This vacuum's range is limited only by remaining battery life, though it can't climb up or down staircases.

6.2
Design
Portability
Total Weight
9.04 lbs (4.10 kg)
Weight In Hand
N/A
Carrying handle
No

The iRobot S9's portability is mediocre. It's a little heavy and lacks a carrying handle to help you carry it from room to room or up and down flights of stairs.

9.2
Design
Battery
Minimum Battery Life
49 min.
Maximum Battery Life
155 min.
Recharge Time
92 min.
Recharge Dock
Yes
Battery Life Indicator
Yes
Removable Batteries
Yes

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.

Design
Quality Of Life Features
Rotating Head
No
Power Adjustment
Yes
Self-Propelled
Yes
Headlights
No
Easy On/Off
Yes
Surface Type Adjustment
Automatic

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 and an auto-adjusting vacuum head to suit different floor types.

Design
Tools And Brushes
Brushroll
Yes
Brushroll On/Off
No
Removable Brushroll
Yes
Turbo Brush
No
Crevice Tool
No
Upholstery Tool
No
Soft Bristle Brush
No
Hard Bristle Brush
No
Extension Wand
No
Ceiling Fan Tool
No
Pet Grooming Tool
No

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.

Design
Alternative Configuration

The iRobot S9 is a robot vacuum with no alternative configurations.

Performance
8.7
Performance
Bare Floor (Hardwood, Laminate, Tiles)
Pet Hair at 0 gal (0L)
100 %
Large Debris at 0 gal (0L)
90 %
Large Debris at 0.07 gal (0.25L)
73 %
Large Debris at 0.2 gal (0.75L)
N/A
Large Debris at 0.4 gal (1.5L)
N/A
Large Debris at 0.8 gal (3L)
N/A
Large Debris at 1.6 gal (6L)
N/A
Small Debris at 0 gal (0L)
100 %
Small Debris at 0.07 gal (0.25L)
100 %
Small Debris at 0.2 gal (0.75L)
N/A
Small Debris at 0.4 gal (1.5L)
N/A
Small Debris at 0.8 gal (3L)
N/A
Small Debris at 1.6 gal (6L)
N/A
Setting Used "Exceptional"

The iRobot S9's performance on bare floors is excellent. It clears pet hair and small debris like rice without an issue, with no noticeable drop in suction power as the dirt compartment fills up. While it sucks up larger debris quite easily with an empty dirt compartment, it struggles more when the dirt compartment is filled.

8.4
Performance
Low-Pile Carpet
Pet Hair at 0 gal (0L)
100 %
Large Debris at 0 gal (0L)
89 %
Large Debris at 0.07 gal (0.25L)
89 %
Large Debris at 0.2 gal (0.75L)
N/A
Large Debris at 0.4 gal (1.5L)
N/A
Large Debris at 0.8 gal (3L)
N/A
Large Debris at 1.6 gal (6L)
N/A
Small Debris at 0 gal (0L)
70 %
Small Debris at 0.07 gal (0.25L)
68 %
Small Debris at 0.2 gal (0.75L)
N/A
Small Debris at 0.4 gal (1.5L)
N/A
Small Debris at 0.8 gal (3L)
N/A
Small Debris at 1.6 gal (6L)
N/A
Setting Used "Exceptional"

The iRobot S9 is great on low-pile carpet. It clears pet hair without an issue and doesn't have too much trouble dealing with coarse material, such as sand. However, it may take a couple of extra passes to fully clear finer debris on this kind of surface, like baking soda spills.

7.6
Performance
High-Pile Carpet
Pet Hair at 0 gal (0L)
100 %
Large Debris at 0 gal (0L)
64 %
Large Debris at 0.07 gal (0.25L)
60 %
Large Debris at 0.2 gal (0.75L)
N/A
Large Debris at 0.4 gal (1.5L)
N/A
Large Debris at 0.8 gal (3L)
N/A
Large Debris at 1.6 gal (6L)
N/A
Small Debris at 0 gal (0L)
68 %
Small Debris at 0.07 gal (0.25L)
68 %
Small Debris at 0.2 gal (0.75L)
0 %
Small Debris at 0.4 gal (1.5L)
N/A
Small Debris at 0.8 gal (3L)
N/A
Small Debris at 1.6 gal (6L)
N/A
Setting Used "Exceptional"

The iRobot S9 delivers good performance on high-pile carpet. It picks up pet hair easily and clears quite a bit of coarse and fine debris on its first go-around, though it may take a couple of extra passes to clean up everything.

8.5
Performance
Maneuverability
Under The Couch
Excellent
Under Low Table
Excellent
On Furniture
Not Possible
Rug With Tassel
Bad
Electric Cord
Ok

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.

Automation
6.0
Automation
Automation (Robot Vacuum)
Remote Controller
No
Automatic Bag Emptying
No
Automatic Recharging
Yes
Schedule Programming
Yes
Boundary Markers
Yes
Random Pathing
No
Smart Pathing
Yes
App Name
iRobot HOME

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. This 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. 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.

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. We can't confirm that this model performs similarly, as its automatic dirt emptying capabilities could have an impact on performance. 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 of the best robot vacuums, the best robot vacuums for pet hair, and the best robot vacuums for carpet.

Roborock S6

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.

Neato Botvac D7

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.

Roborock S5

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. It also features a remote piloting app in its companion app.

iRobot Roomba i7+

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.

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