2S
Limited evidenceRead the findings →An older square HOBOT window robot that wipes with a flat cloth. It's handy for keeping big, high windows clear without a ladder. But it can't shift stubborn marks and is slower than cleaning by hand.
See the alternatives below, or switch market.
Where it sits in HOBOT’s range
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What we know
One home test from a tech site, a comparison-site write-up and two owner reports, all from 2021 and 2022. GadgetGuy cleaned upstairs windows 9 metres up with no streaks and no falls, and scored it highly. Testen mit Kopf found it good on regularly cleaned glass but unable to shift stubborn dirt. A Japanese owner on Icons in My House owner found it cleaner than expected on big patio glass, while a Taiwanese owner on PTT owner couldn't get water deposits off. All of them had to move it between panes, and they disagree on noise.
GadgetGuy, hands-on, Sept 2021
Clear windows, if you clean often
GadgetGuy got its high windows clean with no streaks, and found the pads reached right to the edges. Testen mit Kopf also got streak-free results with the right routine, but said it can't cope with stubborn dirt. The owner on PTT owner couldn't shift water deposits, while the owner on Icons in My House owner found it cleaner than expected and often just runs it dry to lift dust. The review and the comparison write-up both suggest a dry run before the wet pass. It suits windows cleaned often, not ones left for a year.
Slower than doing it yourself
HOBOT says it cleans a square metre in 2.4 minutes. GadgetGuy found it actually took about twice that, because it covers the glass twice, and listed being slower than cleaning by hand as a downside. Testen mit Kopf said it only makes sense on large panes, since small or barred windows mean constant moving. The owner on Icons in My House owner sets a double run on each big pane, gets a beep after about 40 minutes, and gets on with work in the meantime. What you save is effort and a ladder, not time.
Noise figures don't agree
GadgetGuy measured 60dB at a metre and called it audible but bearable. Testen mit Kopf gives 73 to 75dB and compares it with a vacuum cleaner, without saying how far away it measured, which could explain some of the gap. The owner on Icons in My House owner likens it to an older vacuum but could still watch TV nearby, and wouldn't run it outside at night. HOBOT doesn't publish a figure. Expect it to be noticeable, and it also talks you through what it's doing.
Stops, streaks and spray
The owner on PTT owner found the air-leak detection a bit oversensitive, and once it went off, had to fetch the robot by hand. The owner on Icons in My House owner saw streaks from dirty tracks after cleaning outside, and spray landing on the frame. Testen mit Kopf warns that a pad that's too wet leaves streaks. GadgetGuy and Icons in My House owner both say wind blows the mist away outdoors. Clean the tracks after outside runs and plan to stay close by.
Safety kit worth using
It runs on a 5m mains cord, and a built-in battery holds it in place for about 20 minutes if the power cuts out, as both GadgetGuy and Testen mit Kopf describe. HOBOT tells you to tie the safety rope to a fixed indoor object before every use, not just upstairs, per the specifications. Testen mit Kopf adds that it can be awkward to tie off indoors. The owner on Icons in My House owner felt the risky moments were putting it on and taking it off, so ties the rope on first and unties it last. Nobody reported a fall.
Testen mit Kopf reviewed the German version sold as the Sichler HOBOT-2S. The PTT owner report is in Chinese and the Icons in My House owner report is in Japanese.
Our take
Should you buy the 2S?
Best for: Large windows cleaned regularly, with a socket nearby. Skip it if: You need to remove stubborn marks from long-neglected glass.
The 2S may help with large, regularly cleaned panes that you can safely reach to place and retrieve it, with mains power and a secure tether point. One qualifying household review supports cleaning ability; comparison and owner accounts report stubborn deposits, streaks and retrieval problems. The S7 Pro adds moving pads but can still streak. A battery-station WINBOT avoids the nearby-socket requirement, not pane transfers or pad care.
The 2S is one of HOBOT's square window robots, a step below the S7 Pro. It replaced the 298 and added a second water tank, so it mists the glass on both sides and has fresh spray whichever way it's heading. The cloth doesn't scrub: suction presses a flat microfibre pad against the glass while two tracks drive it along. It runs from the mains, and a small battery holds it on the window for about 20 minutes if the power fails.
It's been around since 2021, and the trade-offs haven't changed. You need a socket within reach, you move it from pane to pane, and it takes longer than doing a window yourself. What you save is the stretching and the ladder. Small windows and windows split by glazing bars are a poor fit, because you'll spend all your time moving it.
Before you buy
The questions people ask about this one
Will it work on frameless glass?
HOBOT says an edge sensor picks up air leaking in at the edge of frameless glass, per the specifications, and Testen mit Kopf lists spotting frameless edges as a strength. The owner on PTT owner found that detection a bit oversensitive, and had to fetch the robot by hand when it went off. Keep the safety rope on.
What happens if the power cuts out?
It can't clean without mains power, but a built-in battery keeps it on the glass for about 20 minutes with a spoken alert, per the specifications. Testen mit Kopf confirms the battery is only there to hold it in place. Always tie the 4.5m safety rope to something fixed indoors.
Does it leave streaks?
Results vary, though GadgetGuy got no streaks on its upstairs windows. Run it dry first to lift dust, as GadgetGuy and the Testen mit Kopf write-up advise, and change the pad if it gets too wet. The owner on Icons in My House owner saw streaks from dirty tracks after outside runs. Stubborn marks and water deposits are another story.
Can I use it on upstairs outside windows?
Yes, that's where it's most useful. GadgetGuy used it on double-hung windows 9 metres up and called the safety rope essential there. Avoid windy days, which blow the spray away, and make sure you can safely reach to put it on and get it back.
How long does one window take?
About twice HOBOT's claim, according to GadgetGuy. The spec sheet says 2.4 minutes per square metre, per the specifications, but it goes over the glass twice. Add time for moving it between panes, which Testen mit Kopf says makes it a poor fit for lots of small windows.
Does it need a special cleaning fluid?
Use water or HOBOT window detergent, as its instructions say; that doesn't mean any household glass cleaner will do. GadgetGuy also used water or the supplied solution, and says the two small tanks cover at least 30 square metres.
Alternatives
Other window-cleaning robots to compare.
S7 Pro
Why consider it: Its two pads scrub back and forth, and TechRadar found it excellent on lightly dirty glass and frameless edges.
The compromise: Both of its reviewers still saw streaks on dirtier glass, and it refused a 32cm-wide pane.
WINBOT W2S OMNI
Why consider it: Its battery station means no socket near the window, and Trusted Reviews found it cleared dust and water marks.
The compromise: You still rinse the pad yourself, and it needs panes of at least 30 by 40cm.
388
Why consider it: Owners like its automatic spraying and the help it gives on outside apartment windows.
The compromise: Its round pads leave the corners unfinished, and one owner saw occasional streaks.
Specs
Full specifications
Each specification names its source. Manufacturer claims are not independent test results; unconfirmed figures are labelled.
Owner reviews
Do you own the 2S?
Tell people how it’s held up: cleaning, maintenance, faults and support. Owner accounts are shown separately from independent reviews.
Sources
Where this page’s findings come from
Editorial reviews
Sources
Videos
- Epic Review Hub : The Hobot 2S Window Cleaner | Full Review ↗
- Robot My Life: HOBOT 2S Robot Window Cleaner Review ↗
- Search YouTube for HOBOT 2S ↗Search results may include company demonstrations or similar models. Check the source and model name; a demonstration is not an independent performance test.