Roborock S4 test: a high-end robot at a reasonable price

At Les Alexiens, we love robot vacuum cleaners. Why? Because they simplify our daily life, quite simply. They are real jewels of technology, which make a lot of talk, so as much to say that if they are also compatible Alexa, they really have everything to arouse our interest. After the Roborock S6 test, we had the excellent surprise to learn of the release of a new high-end opus in the Xiaomi ecosystem: the Roborock S4. The first one having quite simply charmed us by its qualities of navigation as of aspiration, we could only speak to you about its little brother. A cheap robot vacuum, or not too much in any case, but which offers high-end services with the signature Roborock. Without further ado, let's move on to Roborock S4 test.

Roborock S4: new robot, new design

We are not going to present you again the very young company founded in 2014 by Richard Chang, but know that at Roborock innovation is a key word since the company dedicates 40% of its 500 employees to R&D.

Besides, note that Roborock is not Xiaomi, an error commonly encountered on the French-speaking web which has a slight tendency to think that Xiaomi is omnipotent. Omnipresent, yes, but with little industrial know-how in this area ... Indeed, the “Chinese Apple” actually relies on companies that are often less known to the general public, but much more competent in their fields, since they manufacture and design their vacuum cleaners for them. Moreover, an informed eye can detect its new partnership concerning robots, we will come back to it ... In short, close this parenthesis, and move on to theunboxing of this Roborock S4.

Unboxing the Roborock S4

Surprise! This time, the cardboard is not white, but cardboard color. And we like its cardboard color… A little coffee, not to say brown, but with the contours of the robot in print on its front face, and a small logo Roborock on his posterior.

Besides, do you know why Roborock has a Z-shaped logo? Because his robots have introduced an innovative cleaning method with Z-shaped movements. Do not thank us for this minute of High-Tech culture, all the pleasure is ours!

OK, that's basic, sure, but Roborock's goal here is to deliver a robot vacuum with a Excellent value, so why not save on expensive packaging which risks, in addition, ending up in the trash?

At the opening, we are quickly reassured: Roborock did not save on the design! Better yet, its new robot has its own look and does not just take that of the S6. And we have to admit it, the Roborock S4 is very successful and its black dress suits him perfectly ! Round in shape, like most robot vacuums on the market, its glossy coating is very pleasant. Some prefer white, which we can completely understand, but keep in mind that these devices constantly carry dust and live as close to the ground ...

[…] The Roborock S4 is very successful and its black dress suits it perfectly […] The Alexians

As always, the robot is perfectly protected. Comes with a HEPA filter spare and a cleaning brush, the Roborock S4 comes with a Quick Start Guide and User Manual. You never know, it can be useful, but it's more about lavishing some maintenance tips than to approach the installation that does not suffer from the slightest difficulty, a strength of the Xiaomi ecosystem.

You have probably noticed the power cable… Cable intended to be inserted into the charging station, or dock, which looks noticeably like that of the S6, although the docking method is somewhat different. A cover offers the possibility of concealing the power cable in a hatch located at the back, as with any high-end robot.

Two large pins allow the robot to come and fill up with energy by sticking its hindquarters to it. A different method than the Roborock S6 to Ozmo from Ecovacs, but identical to that of Conga 3690 Absolute by Cecotec and which although slower remains quite effective. In practice, the robot attacks the loading dock head-on, then rotates 180 degrees and waddles backwards. Once the contact has been made, he will notify you, in French please, of the success of the operation.

Let's come back to the design that is out of the ordinary ... A little touch of originality sets the Roborock S4 of its competitors with a play of transparency of the most beautiful effect which lets see its dust container under the hood. Do you think that is not very aesthetic? Think again, it gives him on the contrary high-tech style, all in finesse, the transparency being at the very least discreet. The Roborock S4, like the Deebot Ozmo 920 from Ecovacs, seems more than ever in the running for a Red Dot Design Award!

The Roborock S4, like the Deebot Ozmo 920 from Ecovacs, seems more than ever in the running for a Red Dot Design Award! The Alexians

It's cool, isn't it? Apart from this little eccentricity, the Roborock S4 takes up the standards of the industry. Circular in shape, it measures 35 cm in diameter and only 9,6 cm high, which will allow him to go almost everywhere. It is more or less the dimensions of the Roborock S6, with a more discreet rangefinder and in a central rear position like the best cars!

Weighing 3.8 kg (against 3.6 kg for the S6), the Roborock S4 is indeed equipped with a Lidar or LDS, the famous laser range finder that distinguishes high-end robots from cheaper ones. A detail which is very important and which, as we will see, gives this new opus of the brand navigation worthy of its S6 lineage, because just as effective. Two cells are present, the one emitting the laser (on the left in the photo) and the lens making it possible to recover the signal.

On the top, we also find a power button with, in its center, a second button to return to the station. It's practical and well-regarded, but unlike the Roborock S6, the S4 does not offer a button to initiate a spot cleaning. It is all the more anecdotal that the function is there and it suffices to press and hold the "home" button to use this functionality. Nothing to regret from this point of view therefore.

Since we've opened the robot hood, let's take a look at what the dust container looks like. Surprise, more space for the cleaning brush - it's a bit of a shame - and the tank is not the same as that of the S6, it is wider and shallower. Is it really serious? Honestly, no. Either way, with all these connected robot vacuum tests, I might as well tell you that the ground is not really dirty here. More seriously, we advise you anyway to empty and clean your robot very regularly to, on the one hand, always benefit from optimal suction, and on the other hand, to avoid clogging the various parts of the device. . Maintaining your equipment also promises it a much better longevity!

Unfortunately, the tank loses 60 mL of capacity compared to that of the S6, but still allows to store up to 420 mL of debris of all kinds. Also equipped with a HEPA filter, it is of very similar design and suffers from the same defect as the other models of the mark since nothing closes its inlet orifice. It will therefore be necessary to be careful when removing it so as not to accidentally spill its content, and empty it a little more often. The Alexians are picky, but we have to find flaws in it!


The Roborock S4 is obviously equipped with a front bumper, also black, and endowed witha single side sensor. A surprise, it must be admitted, but you will see it turns out to be quite sufficient. Thanks to the precision of its rangefinder, the S4 does not need more and this sensor allows him to follow complaints and furniture with an accuracy of less than a centimeter.

Speaking of sensors, you should know that the Roborock S4 does not include less than twelve in total, including four called "cliff sensors" which allow it to estimate its ground clearance or not to fall on the stairs, and are quite logically located under the device, on the floor. front part.

You will notice that Roborock has given its S4 its brand new side brush created by DuPont, which allows it to dislodge the most stubborn dirt and has a density improved by 250% compared to those of the Roborock S50. With some rotations up to 1350 rpm, it pushes dirt better than ever towards the central floating brush which has also been shifted a few centimeters forward compared to the S6 ...

A central V-shaped brush equipped with both plastic strips and lines of bristles, almost identical to that of the S6 but with an increased density of 22%, which visibly allows the S4 to dislodge dirt from the carpets with even more efficiency.

The wheels, finally, are slightly different from other devices in the range. Notched, they are efficient and benefit from a good clearance allowing the Roborock S4 to overcome obstacles up to 1.8 cm. It's a little less than on the S6, it's true, but the robot is sometimes paradoxically more comfortable. The brand's engineers have obviously worked on this point and the robot can handle all situations on its own thanks to improved motive power. This results in loud rolling noises as the S4 climbs over obstacles, but you have nothing for nothing!



Roborock S6 Datasheet

Drums :
5200mAh Li-Ion
2000 Pa
35 cm x 35.4 cm x 9.6 cm
3.8 kg
180 minutes (in silent mode)
Loading time :
less than 6 hours
Remote control:
app and voice control
Charging station :
dock type
Accessories :
HEPA filters x2, brushes x1, dust container x 1
Dust container:
Wi-Fi IEEE802.11 b / g / n 2.4 GHz
Cleaning tool x1 and user guide


Roborock S4: still easy to install and complete thanks to Xiaomi Home / Mi Home

Simple installation

If corridor noises suggest that Roborock would be on the verge of regaining its independence and putting its robots back only under its own application, the S4 is installed and controlled like its predecessor via the Xiaomi Home application, Mi Home for the intimate friends, or the Roborock app. You have the choice! Let’s hope that, whatever happens, the simplicity is always preserved… If we did not live the same phenomenon of instantaneous proposal of the robot by the application, the installation of Roborock S4 is done almost as quickly.

Open the application, press the small "+" at the top right, choose " household appliances " and "Roborock S4".

In less than a minute, the device is added, all you have to do is choose a small name, share with your better half or Conchita if you wish, and select a room (or not). It's simple, fast, devilishly effective.

Wealth of Xiaomi Home


Xiaomi Home is still as rich and the possibilities offered to control the Roborock S4 are almost as numerous as for the S6. Yes, almost, because as you will see the S4 can't quite do as much as the S6

At the opening, you will find a thumbnail with a visual of the S4. You just have to open it to access its control screen.

  • Three areas are displayed at the top: "Cleaning area" with the cleaned area in m², a gauge in "Remaining battery" and the duration of the last cleaning in "Cleaning time".
  • In the middle, you find a map. This will only be recorded after a first complete cleaning of your accommodation. Let the robot do it, even if it is a bit long, you will later appreciate having a complete map.
  • At the bottom right of the map, a small pictogram allows you to choose the suction power delivered by the Roborock S6: silent, balanced, turbo or max.
  • Below the map are three options: " room " which allows you to send the robot to a particular room, " all " which starts an automatic cleaning and leaves the robot free to do as it sees fit, "Zone" to select the perimeter of your choice.
  • At the bottom, finally, two big buttons allow you to send the robot to recharge or start and pause cleaning.

Next to the power pictogram,
you can see a button " menu ". This will obviously only appear when the robot has mapped your home. This is a particularly interesting option that will allow you to:

  • define no-go zones. Useful if you absolutely want to prevent the robot from going to certain places. You can materialize them in two ways: an enclosed area, or simple virtual barriers. Possibilities that we will qualify as essential on a high-end robot and which are therefore very present.
  • restore the map. This option will allow you, as its name suggests, to choose a card for your robot. Useful if you have several floors since you can map each of them, or if you take it on vacation to your second home for example. Just select the card for the robot to start using it. Remember to do this action once the robot is placed in its new environment, and if you have changed the location of the charging station, give it a minute, time for it to use its lidar and locate itself. As with the Roborock S6, we were impressed with how easily the Roborock S4 scans its surroundings.

Unfortunately, unlike the S6, we do not find the map editing features or the ability to select parts on the fly on Xiaomi Home. This does not mean that they cannot be made later, especially since this precious option is offered by the Roborock application.

To compensate for the absence of parts, all you have to do is select zones. It is slightly longer but the result is more or less the same, especially for a non-washing robot. Otherwise, use the Roborock app!

Top right, you find the classics three small dots allowing you to access the robot's advanced parameters.

  • Dance « vacuum cleaner settings« , various options are offered such asmapping recording (apparently in beta), the time zone setting, Choice of language in which the robot will speak to you (French is available), volume adjustment, NDP mode to "do not disturb", Car where you can program automations (we will come back to this), the maintenance program which displays the usage time and the remaining life of the main robot organs, the remote control that allows you to transform your smartphone as a remote control and direct the robot, and finally an option to locate the robot if it got lost in your 450m² or more likely if you cannot find it because it got stuck under a bed, for example.
  • Le delayed start allows you to create simple automations with very complete choices: repetition (once / every day / week only, weekends, etc.), the suction power to apply during the routine, and the area to be cleaned.
  • THEcleaning history gives you the opportunity to see what the robot did and when, with a map showing the journeys made. Perfect if you don't trust him!
  • The option " GO " allows you tosend your robot to a specific location and launch a localized clean-up. A very appreciable feature.
  • Un User manual lets you know everything about your device and can answer your main questions. But if you've read this test correctly, you shouldn't have much of it anymore. You can also contact Roborock customer service in this way.
  • Finally, general settings allow you to change the name of your robot (here, it's Nestor), from share device with another Mi account, to check the availability of a update (they will generally be offered to you, but impatience is frequent among the user), to access information on the network connection status (name of the Wi-Fi network, signal strength, RSSI, Mode, IP address, MAC address) ... But also to add a quick shortcut of your Roborock S4 on the home screen of your mobile device. This is smart because it will prevent you from having to dig into the Xiaomi Home application and access the robot directly.

Automations with Mi Home

As with the other models of the brand, you can do a lot of automation via the Mi Home application. This is really a big strong point of Roborock which allows, for example to launch the Roborock S4 using an Aqara switch.

Let's take a simple example using a ZigBee Aqara switch (12 € on AliExpress) which will allow you to program actions according to the pressure carried out. As in our Roborock S6 test, we placed an Aqara switch next to our front door, which allows us to control the robot when leaving our home without even having to open the application, or to order him to return to his base when we return, just to have peace!

Roborock S4: excellent value for money?

With this new entry-level high-end model, in other words a top-of-the-range not too expensive, Roborock wanted to offer everyone - or almost - the opportunity to benefit from around 400 € services normally reserved for robots with prices usually closer to € 500 or more. If the idea is excellent and necessarily more than attractive, let's see if this Roborock S4 holds its rank.

Always as efficient navigation

This is the great strength of the brand, the DNA of Roborock: navigation. On this point, the Roborock S4 excels like other models of the brand. His Laser rangefinder, or LDS, is once again formidably effective, perhaps even more than that of the S6 for that matter. Indeed, although equipped with a single side sensor, the S4 follows walls with impressive precision. So many brands evoke the famous centimeter, The Roborock S4 hugs complaints and furniture with a precision that borders on perfection. The 10 mm announced on the technical sheet are not at all fanciful and, in this exercise, it is even the most gifted of our selection of robot vacuum cleaners!

Another quality of the robot vacuum cleaners of the Chinese company also present on this model: the velocity. Like the S6, the Roborock S4 is one of the fastest of its generation. It is even quite impressive to see in turbo mode, its movements in Z are precise and carried out in the length with an execution speed which commands respect.

Application level, no complaints, the maps are accurate and you can very simply create "No go lines" ou "No go zones", that is to say virtual barriers and prohibited areas that the robot will respect to the nearest millimeter. The "GO" function allows you tosend the robot to a specific location, and here too its precision is fascinating. Finally, we appreciate the possibility offered, although a little difficult to access and not really easy to find in the menus, of controlling the robot using a virtual remote control in the form of a joystick or navigation arrows. In the absence of a physical remote control, this is a plus.

[…] From a general point of view, the Roborock S4 excels when it comes to navigation […]The Alexians

If, from a general point of view, the Roborock S4 excels when it comes to navigation, we regret however that the parts are not selectable, namable and modifiable via the Xiaomi Home app. Indeed, it is an exclusive of the Roborock house application (available for android), but we hope to see it coming to Mi Home soon. For fans of Xiaomi home automation who, like us, are clad with Aqara sensors, that would be a plus. Especially when you already have another robot of the brand installed on Mi Home!

Excellent suction

When it comes to a vacuum cleaner, the suction power is obviously a more than important criterion, and the Roborock S4 does not disappoint either from this point of view. Like its elders, the engine of the youngest born displays 2000 Pa, what most of the robots offer in this price positioning. But this figure is not sufficient in itself, because it corresponds only to the power of depression of the engine and not to the air flow of the suction mouth.

The vacuum, expressed in Pascal, is created by the motor of the vacuum cleaner. The air flow, which can differ with the same vacuum power, is expressed in L / s or dm3 / s (CFM in imperial units) and corresponds to the volume of air actually sucked in.

Thus, the same 2000 Pa motor does not necessarily provide the same result depending on the robot design and the Roborock S4 actually sucks up to 8.9 L / s (liters per second, in Max mode) while the Roborock S6 is content with "only" 7.1 L / s (in Max mode too, of course), where a Deebot Ozmo 950 reaches up to 11.3 L / s with 2000 Pa also. A significant difference which is not explained by the depression created by the robot motor, but by the optimization of its suction mouth and allows the Roborock S4 to suck 25% more air. Thrown at the front, beyond the wheels, it is combined with a new, smaller tank which probably explains this higher flow. Finally, the Roborock S4 is therefore for the moment the best vacuum cleaner of the brand in terms of inspired air flow.

In practice, almost everything goes there and the power gain is visible in the dust bin. Indeed, as a ozmo 920, the new opus of Roborock manufactures very compact blocks which testify to this efficiency. It will also be necessary to use his brush to empty his bin and everything to take off the HEPA filter. It may sound painful, but it is the price of efficiency.


A good autonomy, without too much noise

Like its predecessors, the Roborock S4 offers great autonomy, even offering the luxury of beating the already very enduring S6. Able to evolve up to 180 minutes in silent mode, he proposes 150 minutes of battery life in balanced mode, the one you will probably use the most because of its excellent efficiency / noise ratio. This results in the robot's ability to perform up to 250 m² of cleaning. In fact, the air flow is reduced by half in silent mode, so this mode should be used when the room is not really dirty or when you do not want too much noise.

[…] The Roborock S4 offers a good range, even offering itself the luxury of beating the already very enduring S6. The Alexians

Noise which, precisely, is slightly more pronounced than on the Roborock S6. Somehow, that makes perfect sense since the S4 offers 20% more power. However, the values ​​remain within the sector average, with around 59.6 dB (A) in silent mode, 62.5 dB (A) in balanced mode, 68.5 dB (A) in turbo mode et 71.9 dB (A) in max mode. As a reminder, the S6 varies between 56 and 71 dB (A) and the Deebot Ozmo 920 between 53 and 70 dB (A).

Compatibility Alexa appreciable

Before concluding, know that the Roborock S4 is obviously compatible with Amazon Alexa. You will therefore be able to benefit from voice control from your appliances Amazon Echo. And, unlike many other robots, you can include it in routines and choose its name, all thanks to the Xiaomi Home app which makes it look like a switch and a miscellaneous device. Isn't that smart?

To do this, nothing simpler :

  1. Activate the skill Roborock on Amazon.Fr,
  2. Then link your Mi account by entering your credentials,
  3. Start a detection of new devices.


So is this Roborock S4 a good deal? Without a doubt, yes! If for you the option of mop washing is not a criterion, because you are aware that all robots are still limited from this point of view anyway or because you already have a robot dedicated to this task , the Roborock S4 is an excellent choice and presents a more than interesting quality / price ratio. More efficient than an S5 / S50, it benefits from the new technologies deployed on the S6 but remains much cheaper. Available at € 415 exclusively on Amazon. Fr, the Roborock S4 is an excellent robot with precise navigation, suction power worthy of the best robots on the market and autonomy allowing it to cover large areas. Once again, Roborock does not disappoint and consolidates its position among the market leaders with a more accessible model.

Roborock S4 - Robot vacuum cleaner for animal hair and hard floors

NS. 415 €









Price quality



  • Very successful design
  • Flawless navigation
  • Fast and powerful robot
  • Good value for money
  • Compatible Amazon Alexa

The lessers

  • No remote control
  • No parts on Xiaomi Home (but the Roborock app yes!)
  • Don't mop the floor
  • A bit noisy compared to the S6
Fascinated by Alexa since the day I received it in beta test, I gradually became passionate about the subject, before deciding to go further by creating a site with Jean-Christophe. An activity that allows me to quench my thirst for new technologies and share my discoveries about the nicest of communities: Les Alexiens.