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Roborock S4  Robot Vacuum Review

Reviewed Jul 06, 2020 at 08:23am
Retest Oct 17, 2022 at 03:36pm
Tested using methodology v0.6 
Roborock S4
7.6
Bare Floor 
6.8
Low-Pile Carpet 
4.1
High-Pile Carpet 
5.2
Pets 
5.6
Stairs 
4.7
Cars 
4.3
Workshop 
 0

The Roborock S4 is a mid-range robot vacuum in Roborock's vacuum lineup with outstanding performance on bare floors. It effectively cleans hair on bare floors and on low-pile carpet so it's an ideal choice if you have a pet and your house has those surfaces. Unfortunately, it doesn't work on high-pile carpet as once it gets on, it doesn't clean anything and notifies you to move it to another location. Its smart pathing feature is effective at cleaning a room as it learns a new path every time it cleans, so it's efficient at moving around objects. It's a bit difficult to maintain and you also need to buy replacement parts regularly. On the upside, it has an excellent battery life and the dirt compartment is of good size for a robot vacuum.

Our Verdict

7.6
Bare Floor 

The Roborock S4 has outstanding performance on bare floors as it sucks up almost all debris of any kind. Its smart pathing feature is effective at cleaning a room and it has a good-sized dirt compartment for a robot vacuum. Unfortunately, it's a bit difficult to maintain and there are a few recurring costs associated with the vacuum.

Pros
  • Outstanding performance on bare floors.
  • Effective smart pathing feature.
Cons
  • A lot of parts that need maintenance and replacing.
6.8
Low-Pile Carpet 

The Roborock S4 isn't bad for low-pile carpet. It cleans most hair and large debris on low-pile carpet but struggles a bit with small debris. It has great maneuverability and its dirt compartment is a good size for a robot vacuum. Sadly, you're going to need to clean quite a few parts regularly and buy replacements for them too.

Pros
  • Effective smart pathing feature.
  • Effectively cleans hair on low-pile carpet.
Cons
  • Struggles with small debris on low-pile carpet.
  • A lot of parts that need maintenance and replacing.
4.1
High-Pile Carpet 

The Roborock S4 doesn't work on high-pile carpet. It has trouble getting on, doesn't clean anything, and then asks to be moved to another location.

Pros
None
Cons
  • Doesn't work on high-pile carpet.
5.2
Pets 

The Roborock S4 is a decent vacuum to clean pet hair. It does an impressive job at sucking up hair on both bare floors and low-pile carpet but it doesn't work on high-pile carpet. You can also remove the brushroll if hair gets tangled and it has a dedicated brushroll cleaning tool with a hook to help remove hair.

Pros
  • Outstanding performance on bare floors.
  • Effectively cleans hair on low-pile carpet.
Cons
  • Doesn't work on high-pile carpet.
  • A lot of parts that need maintenance and replacing.
5.6
Stairs 

The Roborock S4 isn't designed to be used on stairs.

4.7
Cars 

The Roborock S4 isn't designed to be used in cars.

4.3
Workshop 
  • 7.6
    Bare Floor
  • 6.8
    Low-Pile Carpet
  • 4.1
    High-Pile Carpet
  • 5.2
    Pets
  • 5.6
    Stairs
  • 4.7
    Cars
  • 4.3
    Workshop
  • Changelog

    1.  Updated Oct 17, 2022: We've corrected an error in this review stating that this vacuum has a HEPA-efficiency exhaust filter. This isn't the case, and all mentions of this vacuum having a HEPA filter have been removed.
    2.  Updated Sep 23, 2022: Converted to Test Bench 0.6.
    3.  Updated Sep 23, 2022: Converted to Test Bench 0.5.
    4.  Updated Jul 06, 2020: Review published.

    Popular Robot Vacuum Comparisons

    The Roborock S4 is good robot vacuum that's ideal for use on bare floors. If you have high-pile carpet, there are better robot vacuums, such as the Roborock S5.

    Also see our recommendations for the best robot vacuums for pet hair, the best robot vacuums for hardwood floors, and the best robot vacuums.

    Roborock S4 Max

    The Roborock S4 Max and the Roborock S4 are very similarly designed vacuums, and you may prefer either one, depending on what surface types you have in your home. The Max can climb onto and clean high-pile carpets. It has a longer maximum battery life, and it's also lighter, which makes it more portable. On the other hand, the S4 has a much better performance on low-pile carpets and picks up more debris, like cereal from bare floors, when its dirt compartment is partially full.

    Roborock S5

    The Roborock S5 is a bit better overall than the Roborock S4. They both have similar performance on bare floors and low-pile carpets, but the main difference is that the S5 is able to clean high-pile carpets while the S4 can't. Besides that, they each require the same maintenance needs and have the same dirt compartment, and the batteries are similar.

    Roborock S6

    The Roborock S6 is a better robot vacuum than the Roborock S4. The S6 cleans all surface types much better, especially because it can climb onto high-pile carpets, and it has a mopping feature, although we don't currently test for this. It also has slightly better maneuverability and build quality. That being said, the battery life of both vacuums is very similar, so if you don't have carpet in your home, the S4 could be a good alternative.

    Samsung POWERbot R7040

    The Roborock S4 is a better vacuum for use on bare floors while the Samsung POWERbot R7040 is a bit better on carpets, although it's still not good on that surface. The Roborock cleans up almost all debris on bare floors, it has a much better battery, the dirt compartment is bigger, and it has a better build quality. However, the Samsung is easier to maintain, and it has no recurring costs. 

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    Test Results

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    RATINGS
    Category:
    All
    Design
    8.0
    Build Quality
    Vacuum Type
    Robot

    The S4 has a great build quality. It's made out of a hard plastic that has a glossy finish on top, which is transparent so you can see if the dirt compartment is full. The dirt compartment is plastic but could break if dropped on the floor. The two main wheels are made out of durable rubber and the laser distance sensor on top has a matte plastic finish like the bumper of the vacuum. Also, there are two wide charging contact slots on the vacuum, making it easier to dock and charge.

    There's virtually no assembly required. All you have to do is connect the vacuum to your mobile device with either the Mi Home or Roborock apps and set up the vacuum with the charging station.

    7.0
    User Maintenance

    The S4 is a bit difficult to maintain as there are a lot of parts that you need to clean. Luckily, each part is easy to take off.

    • Brushroll: The brushroll is easy to remove as you just need to take off the plastic cover underneath the vacuum. The vacuum comes with a cleaning tool that has a brush on one end and a hook blade on the other end to remove any tangled hair on the brushroll.
    • Side brush: You need a screwdriver to take off the side brush and screw it back on again. You need to clean this once a month.
    • Dirt compartment: The dirt compartment is easy to remove. You should clean it with water every two weeks but it needs to be dry before using it again.
    • Filter: The filter is located inside the dirt compartment and you just need to open the compartment to access the filter. You should clean it with water every two weeks and it must be dry before you use it the next time.
    • Wheel: The omnidirectional wheel located at the back of the vacuum can be removed by applying a bit of pressure. This makes it easier to remove any tangled hair or debris from the wheel.
    • Sensors: If dust or debris builds up on the sensors, you have to clean them with a soft cloth.

    The Mi Home app lets you know which parts need to be replaced based on total hours used. This is only for when you need to buy a new part and not clean a specific piece.

    6.0
    Recurring Cost
    Bag Part NumberNo bag
    Filter Part NumberE11
    HEPA Filter Part NumberNo HEPA Filter

    Unfortunately, the S4 robot vacuum has a few recurring costs. The app has a 'Maintenance' tab that indicates the total hours left for each accessory that needs changing. Roborock recommends changing the filter every four to five months, the side brush every three to six months, and the main brushroll every 6-12 months, as long as each part is cleaned regularly. Each part is sold on Roborock's store on Amazon.

    8.9
    Storing
    Height
    5.04" (12.8 cm)
    Width
    13.90" (35.3 cm)
    Depth
    16.46" (41.8 cm)
    Cord Storing
    Not Needed
    On-Board Tool Storage
    Not needed
    Vacuum Rack/Station
    Yes

    The S4 has excellent storing capability. This vacuum mounts to the charging station on its own, and you can hide the cables behind the station with a cord management cover.

    7.1
    Dirt Compartment
    Bagless
    Yes
    Volume
    0.11 gal (0.42 L)
    Full Indicator
    Yes
    Bag Included
    No Bag Needed

    The dirt compartment is decently-sized and a good size for a robot vacuum. Still, it needs frequent emptying and the app notifies you when it's full. If you want a similarly-performing robot vacuum with a bigger dirt compartment, consider the Roborock E4.

    In The Box

    • Roborock S4 vacuum
    • Charging dock
    • Charging cable
    • 2x E11 filters. One is already located inside the dirt compartment
    • Main brushroll cleaning tool
    • User guide

    10
    Range
    Cordless
    Yes
    Cord Length
    N/A
    Hose Length
    N/A
    Minimum Wand Length
    N/A
    Maximum Wand Length
    N/A
    Total Range
    N/A

    The S4 has an unlimited range as long as it still has a battery, but it isn't able to go up stairs.

    7.8
    Portability
    Total Weight
    8.48 lbs (3.85 kg)
    Weight In Hand
    0.00 lbs (0.00 kg)
    Carrying handle
    No

    Good portability. The S4 is small but may be heavy to carry around for some people if you need to bring it to another floor.

    9.1
    Battery
    Minimum Battery Life
    116 min
    Maximum Battery Life
    199 min
    Recharge Time
    183 min
    Recharge Dock
    Yes
    Battery Life Indicator
    Yes
    Removable Batteries
    No

    The S4 has excellent battery life. On its 'Max' mode, which is the most powerful, it lasts almost two hours, and on the least powerful mode, 'Silent', it lasts well over three hours. It takes three hours to charge, but it has a much better life-to-charging ratio than the Samsung POWERbot R7040. The Power button on the vacuum is red when there's less than 20% battery life left; otherwise, the button is white. You can also see the battery percentage on the app.

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

    The S4 robot vacuum has a few extra features. It has four different suction modes, 'Silent,' 'Balanced,' 'Turbo,' and 'Max' that changes the power of the suction. It also has an automatic surface type adjustment that changes the speed of the brushroll depending on the surface. Near walls, it spins faster to pick up as much debris as possible, while in the middle of a room it's slower so that debris doesn't go flying. This vacuum also has built-in speakers, notifying you of its status or whether cleaning is complete, if the dust bin is full, etc.

    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 S4 has a main brushroll and a side brush that picks up debris in blind spots and carries debris under the vacuum so that it's picked up. Also, there's a small brush to clean the main brushroll.

    Alternative Configuration
    Blower Mode
    No

    There's no alternative configuration for this vacuum.

    Performance
    8.5
    Bare Floor Performance (Hardwood, Laminate, Tiles)
    Setting Used"Balanced"
    Large Debris at 0 gal (0L)96%
    Large Debris at 0.07 gal (0.25L)52%
    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)99%
    Small Debris at 0.07 gal (0.25L)≈ 99%
    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

    The S4 has an outstanding performance on bare floors. It has no trouble cleaning small debris like rice and it sucks up most pet hair and large debris like Cheerios. It picks up most large debris, but large debris could get stuck under the vacuum and get dragged to the dock. You may have to manually clean around the charging dock if the vacuum is cleaning large debris like cereal.

    4.9
    Low-Pile Carpet Performance
    Setting Used"Max"
    Large Debris at 0 gal (0L)40%
    Large Debris at 0.07 gal (0.25L)≈ 39%
    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)24%
    Small Debris at 0.07 gal (0.25L)≈ 23%
    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

    The S4 isn't bad on low-pile carpet. The vacuum struggles cleaning small debris like baking soda but still does an excellent job cleaning hair. With large debris, it quickly loses performance as the dirt compartment fills up.

    0.0
    High-Pile Carpet Performance
    Setting UsedUntestable
    Large Debris at 0 gal (0L)0%
    Large Debris at 0.07 gal (0.25L)N/A
    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)0%
    Small Debris at 0.07 gal (0.25L)N/A
    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

    Unlike the Roborock S5 or the Roborock S6, this robot vacuum can't be used on high-pile carpet. It has a hard time getting onto the carpet and once on, it says it's done cleaning, even though it doesn't really move. It loses its sense of direction on high-pile carpet and asks to be moved to another location. The Roborock S4 Max is an otherwise very similar vacuum that can move around on high-pile carpets.

    8.1
    Pet Hair Floor Performance
    Bare Floor
    100%
    Low-Pile Carpet
    92%
    High-Pile Carpet
    0%
    0.1
    Suction
    Maximum Suction
    0.2 inH₂O (0.05 kPa)
    Setting Used For Maximum"Max"(App)
    Normal Suction
    0.0 inH₂O (0.01 kPa)
    Setting Used For Normal"Balanced" (App)
    Hose Diameter
    N/A
    9.3
    Noise
    Bare Floor
    61.5 dBA
    Low-Pile Carpet
    61.7 dBA
    8.0
    Maneuverability

    Great maneuverability. The laser sensor navigation is effective and the robot vacuum uses smart pathing technology. It learns a new path after each cleaning session, making it more efficient around objects, and you can also set barriers around smaller objects like cables. It's small enough to fit under couches and tables, but when it gets stuck on a rug, it stops itself.

    0.0
    Pet Hair Furniture Performance
    Sofa Pickup Post Test
    Air Quality
    Anti-Allergy Filter (HEPA)
    No
    5.0
    Cracks
    Wood Cracks Post Test
    1.0
    Stains
    Stain Pickup Post Test
    0.0
    Water
    Wet Compatible
    No
    Water Pickup Post Test
    Automation
    7.1
    Physical Automation
    Automatic Recharging
    Yes
    Automatic Bag Emptying
    No
    Pathing Algorithm
    Smart
    Physical Boundary Markers
    No
    Scheduled Start Buttons
    No
    Cycle Control Buttons
    Onboard Only
    Navigation Control Buttons
    Return to Base Only

    The S4 has excellent automation features. There are two apps available, the Mi Home and Roborock apps, which have the same layout and features, but Mi Home is compatible with other smart devices. Through the app, you can schedule cleaning times, set boundaries, designate cleaning in a specific room, and see when different parts need maintenance. The vacuum also returns to the charging station on its own, even if you move the dock because of its advanced mapping technology.

    You can also use the buttons to control the vacuum without an Internet connection. Pressing the Power button enables a full house clean, holding the Home button for 3 seconds enables a spot clean, and pressing the Home button sends it to the dock.

    8.0
    Companion App Automation
    App Name
    Roborock
    iOS Availability
    Yes
    Android Availability
    Yes
    Software Boundary Markers (No Go Zones)
    Yes
    App Scheduled Start
    Yes
    App Cycle Control
    Yes
    Navigation Control within App
    Yes

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