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Roomba s9+ vs s9 (2021): Do You Need A Self-Emptying Robot Vacuum?

Roombas have come a long way from the random-moving devices that were introduced about a decade ago. The latest models such as the Roomba s9 and s9+ are now capable of accurately mapping floors and knowing where to clean. Although they share most traits, the s9 and s9+ are different from each other as discussed below.

Roomba s9+ VS s9 Comparison Chart

ModelRoomba s9+Roomba s9
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PriceAmazon product Amazon product 
RatingAmazon product
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3-Stage CleaningYesYes
Dual Multi-Surface Rubber Brushes YesYes
Carpet BoostYesYes
Imprint Smart MappingYesYes
Voice ControlYesYes
Imprint LinkYes, w/ Braava m6 Yes, w/ Braava m6
HEPA FilterYesYes
DesignD-shaped D-shaped


Unlike the Roomba s9 and most other robot vacuums on the market, the Roomba s9+ has a self-emptying feature.

roomba s9+ self-emptying
The Roomba s9+ can self-empty its bin with its enlarged charging base

The Roomba s9 is fully capable of finding its way back to its dock and recharging its batteries on its own. The Roomba s9+ also has these traits along with the CleanBase system. Essentially, it has a bigger charging dock with a disposable dust bag where the s9+ directly deposits debris into. The base bag can hold up to 30 loads from the onboard bin. If this feature seems familiar, this is because it was first seen on the Roomba i7+.

3-Stage Cleaning

The Roomba s9 and s9+ use a 3-stage cleaning system for sweeping and picking up debris.

roomba s9 suction
The Roomba s9/s9+ uses 3-Stage Cleaning and 40X more suction power

iRobot continues to develop its 3-Stage Cleaning System that utilizes Dual Multi-Surface Rubber Brushes. The Roomba s9 and s9+ have the latest version. This comes with 40 times more suction power compared to the 600 product line so they do well at picking up embedded pet hair, dirt, and other debris. They also feature Carpet Boost to increase power when cleaning carpeted surfaces.

Edge Cleaning

The Roomba s9 and s9+ have done away with the circular design of traditional robot vacuums and embraced a D-shape.

roomba s9 perfectedge
The Roomba s9/s9+ feature PerfectEdge technology for cleaning corners and near walls

Deviating from the round design of their predecessors, the Roomba s9 and s9+ introduce PerfectEdge technology with a new D-shaped body. PerfectEdge makes use of a specially designed Corner Brush with five arms for capturing debris along walls and deep in corners. The new design has also allowed iRobot to place larger extractors so the robots can vacuum more floor space per cleaning session.

Mapping & Navigation

Combining Imprint Smart Mapping with vSLAM navigation, the Roomba s9 and s9+ map homes more accurately than ever.

roomba s9 mapping
More accurate mapping and navigation the Roomba s9/s9+ with Imprint and vSLAM

Through vSLAM, the Roomba s9 and s9+ are able to gather over 200,000 data points per second for mapping an entire level of your home. Imprint technology, on the other hand, helps the robot determine the best plan for cleaning every room. Advanced sensors scan 25 times per second to detect obstacles. To see the information gathered by the robot, simply access the iRobot Home app and control which rooms to clean and when.


Most Roomba models have a CLEAN button in the middle while the Roomba s9 and s9+ have the controls on the side.

roomba s9+ app
The Roomba s9/s9+ can be operated through your mobile phone or with voice control

The buttons on the top of the Roomba s9 and s9+ are: CLEAN for starting or pausing a cleaning cycle; HOME for sending the robot back to base and; SPOT for spot cleaning certain areas. They are the same as what you would find on older models. The s9 and s9+ can also be operated via the iRobot Home app or voice control when paired with compatible devices like Amazon Alexa and Google Assistant.


The Roomba s9 and s9+ can be used in tandem with mopping robots through linking technology.

roomba s9+ link
Use the Roomba s9/s9+ in tandem with the Braava through linking technology

Imprint Link is the next generation of home automation that allows you to pair the Roomba s9 or s9+ with the Braava jet m6. What happens is when the vacuum is done with your carpets, it communicates to the mop that it’s time to work. This feature cannot be used with any other mopping robot though. Thus, you will need to buy the Braava if you want your floors vacuumed and mopped.

HEPA Filtration

The Roomba s9 and s9+ are ideal for homes with pets thanks to a highly efficient filter.

Roomba s filter
The Roomba s9/s9+ uses the latest AeroForce with HEPA filter

The HEPA filter on the Roomba s9 and s9+ are of the same size as those on the Roomba e5 and i7+. It’s part of the AeroForce cleaning system although older AeroForce has larger filters. Made of a special material, the HEPA filter can trap dust mites, pollen, mold, and allergens. Dander and pet hair are also no issue with the s9 or s9+.


The Roomba s9 is the more affordable device but it doesn’t have the CleanBase system that the Roomba s9+ has. If you don’t need a self-emptying function, the s9 is a good choice.

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With automatic bin emptying technology, the Roomba s9+ brings a higher level of convenience than the Roomba s9 though you’ll have to pay premium for it. You can buy the special charging base for the s9 but it will be an additional expense. Hence, you’ll have to decide whether this is a feature you really need or not.

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Andy Mathews

Lead Editor at Compare Before Buying. Product researcher and tech enthusiast passionate about consumer products, comparison charts and surfing.