Roborock S4 review

The Xiaomi-backed robot vacuum drops the mop but still delivers the goods

Roborock S4
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A robot vacuum cleaner is no longer the infomercial-driven waste of space many once thought it was, and no company represents this steep and rapid incline in quality better than Roborock.

The Xiaomi-backed Chinese company has returned with another smart robot vac, the entry-level Roborock S4, which brings a select collection of features from higher-tier models, such as the flagship Roborock S6.

It also manages to drop the already-budget price tag from the likes of the S5 and S6 and offer you a way to get in on the ground floor for a very reasonable $399. That's a good $200 less than much of the competition.

Read now: Living in a Xiaomi smart home

One thing potential buyers should know about Roborock is that that there's seemingly no end to the confusion over its branding. Some listings will see the Xiaomi stamp tacked on, others will offer a "0" on the end of the model number - often just to distinguish between different colors of the same exact device - and there's no end of spin-offs, including Xiaowa devices.

We imagine this is something that will eventually iron itself out, as Roborock establishes itself more firmly as a separate entity from Xiaomi, but, for now, keep this in mind.

Really, all that matters is this is the latest robot vac from the company, and below you can read exactly what we made of it.

Roborock S4: Design and build

Roborock S4 review

The look of the Roborock S4 doesn't deviate too greatly from what we've seen in previous models, but that's by no means a knock on the latest edition. Like with the Roborock S5, this is a clean and modern take on the robot vacuum, with the most noticeable change coming through the partially transparent window at the top.

This is a little difficult to capture on camera, but it's essentially like someone has taken a greasy cloth and rubbed it on the top of the lid, allowing you to get a sneak peek at all the dust and dirt that awaits your rubbish bin.

It's relatively pointless, when you really think about it, but it does add to the overall feel of the device - and the S4 is something that looks and feels like quality machinery.

The typical design features are also present, like the flexible bumper (to cushion any driving blows into legs), with the underside coming equipped with an anti-tangle main brush and a corner spinning brush. These, like the dirt collection box at the heart of the vac, are detachable and fairly easy to clean.

One thing it doesn't have that other models do is the mop - though, as we've detailed in other reviews, while this is a neat function you wouldn't say no to, it's also not completely essential.

Roborock S4 review

Back to the things that are present, and we're not sure the main brush is quite as anti-tangle as Roborock suggests. Either that or we just live with a partner with exceptionally thick hair.

This hasn't managed to interrupt any cleans thus far, regardless, but we would recommend taking a scissor to the entwined hair every four or five cleans, just to make sure you avoid any wailing error codes from the S4.

Now, obviously, we'd be remiss if we didn't point out, yes, robot vacuums still aren't the sexiest thing you can place in your smart home. However, this is about as good as it gets in 2019. It doesn't look cheap, it's relatively sturdy, and - as we'll get to - it does the job so well you literally won't care. Add a sticker on, draw a face on it - it doesn't matter.

Roborock S4: Performance and in use

Roborock S4 review

So, the section that really matters - how good is this thing at actually keeping your floors free from dust bunnies? Well - and we know this is starting to sound like a broken record - but similar to what we found in our review of the Roborock S5.

Again, this is no slight on the S4 - in fact, it means it's exceptional at not only cleaning, but also navigating. No matter which mode we set it on - one of either Quiet, Standard, Medium, or Turbo - we found that the vac was able to log a ridiculous amount of dust and dirt, and rarely needed rescuing. It really made us question the cleanliness of our houses in the past, where we'd only break out the corded Henry vacuum if somebody was coming round.

Amazon: Roborock S4 - Save $40
Amazon: Roborock S4 - Save $40

We wouldn't especially recommend one of these modes over the other, and, for us, this mainly depended on how loud we wanted the S4 to run. Basically, it cleans great regardless. And it makes sense that performance on floors, carpets, and tiles matches the S5 and S6 models, since it has the same 2,000Pa suction rating.

Navigation, as we alluded to, is where it really shines. We've just moved into a new flat (it's great, thanks for asking), meaning there are still half-empty boxes in the hallway, scattered bits on the floor and wires (soon to meet the humble cable tie) everywhere you look. All our furniture has legs, too - it's like a fallen pirates meeting.


This is still a robot vac, so it's not been able to handle things like wires or extension plugs on its own every time, but we were seriously impressed with the lack of issues we had over our five test cleans.

Even potential obstacles that could confuse the vac, like our ceiling-to-floor vertical blinds, didn't end up proving too much of an issue. And it'll still relentlessly make sure it's cleaning close to a leg, or a couch, even if it gets knocked back multiple times from different angles. It's really impressive stuff.

And, sure, it'd be nice to have that mop for the occasional deep clean on the kitchen and bathroom floors, but this isn't the biggest omission - and you know where to look if you do want that feature.

Roborock S4: The app experience

Roborock S4 review

While the Roborock does communicate with you on its own - telling you when it's finished with a clean, for example - much of the interaction and control you'll have is through the Roborock app (or the Xiaomi Mi Home app, which is essentially an identical experience).

And, for the most part, it works exceptionally well. You can set do not disturb times, cleaning schedules, see your history and even get a live look at the ground the S4 is covering. It's all there, and it's no different to other models in the range, which, in itself, is neat - there's no real drop-off despite this being the cheaper model.

It's here where you're also able to get a look at the status of the vacuum's parts, and how long you have before you have to order replacements from Amazon.

Mapping is very true-to-life, and setting no-go zones in the app was simple. We set two, near the TV bench and underneath the dressing table in the bedroom, and they were abided by strictly. This is super handy for areas in the house you feel might result in hiccups, but you can't be bothered to actually alter just for the robot.

However, at least at the time of writing, it's not all perfect. Our only real issue with the entire experience so far has come after a recent update, which added the ability for the S4 to automatically recognize rooms and then let you individually select them for cleaning. This, despite a map and a backup being saved within the app, has yet to work.

The feature is still in beta, and it's something we're expecting to be resolved over the coming weeks. When it is, we'll be updating this section to let you know how we got on with it.

A quick note on smart assistant support, too. They are in the mix, but, as we discovered, it's a bit of a chore getting them linked. The S4 can connect to the Roborock Alexa skill (Xiaomi Home, if you're in the UK), allowing you to turn it on or off, but, considering the app control is so good, you're not likely to need it. We also couldn't get the S4 connected to Google Assistant at all, despite repeated attempts.

Roborock S4: Battery life and maintenance

Roborock S4 review

The S4 brings the same 5200mAh battery that, ahem, like the S5, gives your space around 150 minutes of cleaning when in Standard mode.

We've tested the battery on all the modes, and it can typically handle our one-bedroom flat in around 40-45 minutes with plenty (often 60-70%) of juice leftover. Based on that, it should never be running low, though Roborock does suggest it'll automatically head home at 20% if it doesn't have enough juice to finish the job.

When it is done roving around, it can find its way home with ease - something that can't be said for every vac. It'll make a beeline for the base station and then slowly back up to hit the charge.

Amazon: Roborock S4 - Save $40
Amazon: Roborock S4 - Save $40

You shouldn't have to mess with this process too much, which is yet another thing taken out of your hands by a device which, as you'll have gathered from this review, pretty much does exactly what it says on the box.

Maintenance-wise, as we described above, the app will let you know the precise condition of the cleaning sensors, brushes, and filters. Once the dustbin is full, the app will also tell you when to empty it, and, while it's not the biggest, that's really just an innate robot vacuum issue, rather than one specific to the S4.


Roborock S4
Roborock's most inexpensive smart robot vacuum is anything but cheap, offering unmatched value with a performance that belies its price tag. The mop is the only real missing piece, but hardly a feature you would expect at this price, and something you can gain by upgrading to the S5. For those who just want the best automated clean without any navigation faff, there's simply nothing at this price point that comes close.
PROS
  • Excellent cleaning
  • Expert navigation
  • Superb value for money
CONS
  • No mopping
  • Selective room still in beta
  • Smart assistant setup is buggy

TAGGED    robot vacuums    smart home

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