HOBOT
HOBOT-S6 Pro
- Autonomy
- IIAssisted
- Score
- 66/100Capable
- Readiness
- Ready Now
- Price
- $850list
ComparisonHOBOT-S6 Pro and Kärcher RCW 4
Kärcher
Kärcher RCW 4
- Autonomy
- IIAssisted
- Score
- Not scored
- Readiness
- New to Market
- Price
- Not tracked
Up to three
Autonomy Ladder
- IManual
- IIAssisted
- IIIConditional
- IVEnvironmental
- VGeneralized
All robot window cleaners. Every figure below is placed against the whole class, so a gap can be read against how much the class itself varies.
Where each one suits you.
The conditions each robot was assessed against, side by side. Rows marked in gold are where these machines genuinely differ.
| Condition | HOBOT-S6 Pro | Kärcher RCW 4 |
|---|---|---|
| Window style | ||
| Standard residential | Good6cm (2.4-inch) to 30cm (12-inch) windowpanes with standard frames; dual mops handle standard dimensions well. | GoodSix pump-driven nozzles and continuous suction are built for ordinary single-pane residential windows, Kärcher's documented core use case. |
| Large panes (8 ft+) | GoodPanoramic and frameless panes are documented strengths. Ultrasonic spray prevents streaks on large contiguous glass. | GoodThe 150 mL tank, rated for about 100 sq m per fill with a fill-level indicator, covers large panes without a mid-job refill. |
| Specialty / texturedthey differ | DependsCurved, beveled, or divided-light (muntin) windows may cause pad misalignment. Test on a small pane first. | PoorContinuous suction contact assumes smooth flat glass; leaded or heavily textured panes are not part of the documented design. |
| Frame style | ||
| Frameless / minimalthey differ | GoodNo frame edges to catch. Flat glass adhesion is documented and reliable on frameless designs. | DependsSuction should hold on flat frameless glass, but no independent review confirms edge behavior without a frame lip. |
| Standard mullions | GoodStandard frame clearance is designed in. Edge sensors detect frame proximity and adjust pad contact. | GoodStandard framed residential windows match Kärcher's documented cleaning mechanism and are the product's core target surface. |
| Heavy bezelsthey differ | DependsHeavy-duty or ornamental frames (arched, deeply embossed) may interfere with dual-pad geometry. Side clearance may be inadequate. | PoorGrilles or muntins dividing a pane interrupt the wiping path the cleaning pad's suction contact depends on. |
| Building height | ||
| Single-story | GoodGround-floor and low-story windows are ideal. Cord extends typical 50–60 feet; no height limitation for floor-level panes. | GoodGround-floor windows need no tether reliance beyond the power cord; outlet access within 5 meters is the only real constraint. |
| 2 – 3 storiesthey differ | GoodSecond and third-story accessible windows suit corded operation. Safety rope tethering provides redundancy for 2–3 story heights. | DependsThe 5-meter power cord must reach a secure outlet upstairs, and Kärcher documents no separate anchor point for this model. |
| 4+ storiesthey differ | DependsFourth-story and above require anchor-point assessment and professional safety review. Tether rated for robot weight, not unlimited height. | PoorNo documented safety-tether or anchor system extends this unit's reach to a true high-rise installation. |
| Power preference | ||
| Corded OK | GoodCorded design is optimized for continuous operation. Weatherproof extension cords required for outdoor use. | GoodThis is a mains-corded design by default; a nearby outlet within the 5-meter cord's reach is all it requires. |
| Cordless preferred | PoorHOBOT-S6 Pro is corded-only. Cordless window robots are a different product category. | PoorNo cordless or battery-only operating mode exists; the 5-meter power cord runs the cleaning cycle throughout. |
| No preference | GoodCorded power suits multi-window sessions and high-rise safety; cordless models are separate products. | GoodWorks fine for a reader with no power-source preference, since the RCW 4 runs entirely corded off mains power. |
A robot being poor for a condition is a fact about fit, not a fault. “Depends” means the record names a limit worth reading, not that the answer is unknown.
How far apart is a long way?
A number only means something next to the spread it sits in. Each track is the real range across every classified robot in the class, with the median marked.
Weight22 with a published figure
3.6 lbs3.3 lbs
- HOBOT-S6 Pro3.6 lbs
- Kärcher RCW 43.3 lbs
1.3 lbsmedian 3.1 lbs4.8 lbs
Height24 with a published figure
3.9 in2.8 in
- HOBOT-S6 Pro3.9 in
- Kärcher RCW 42.8 in
2.2 inmedian 3.2 in9.4 in
Not compared, because fewer than two of these robots carry a published figure: Price, Suction, Runtime, Charge time, Noise.
What the numbers leave out.
Written on each record, and the only thing here every robot on the site carries.
The trade-off
What each design gives up to be good at what it is good at.
HOBOT-S6 Pro
Manual launch and repositioning. The robot does not autonomously navigate between windows or edges; a user must place it, start it, and move it to the next pane, it is not a set-and-forget window cleaner.
Cord management. The 5 meter power cord caps the working radius from a socket, and its secured DC connector is built to stay joined rather than be extended. Placement has to account for that cord and, separately, for the safety rope, without either fouling the other.
Kärcher RCW 4
Four automatic modes and a 150 mL tank change how long a single pass takes, not whether the unit still has to be carried, plugged in, and started on every pane.
The tank now covers about 100 square meters per fill, but that headroom does not change the underlying mains dependency: every session still starts by finding an outlet within reach of the 5-meter cord.
Thin evidence base: a launch-week record with no independent reviews or owner reports to check Kärcher’s own cleaning-speed and coverage figures against.
Who each one is wrong for
Stated by the record itself. A robot being wrong for a household is a fact about fit, not a fault.
HOBOT-S6 Pro
- Fully autonomous outdoor window cleaning
- HOBOT-S6 Pro requires manual launch and manual repositioning between panes. It does not autonomously navigate or select windows to clean.
- Homeowners with small tight window frames or muntins
- Dual mops and head width are optimized for larger panes. Narrow muntins and divided-light windows may require manual cleaning or repositioning to avoid frame contact.
- Users needing coverage far from a socket
- The power cord is 5 meters, about 16 feet, on a secured DC connector designed not to pull apart in use. That is the working radius from a socket, and there is no cordless variant of this model.
Kärcher RCW 4
- Windows with no nearby power outlet
- The RCW 4 has no cordless or battery-only mode; a window beyond the 5-meter power cord's reach from an outlet cannot run a cleaning cycle.
- High-rise panes beyond the cord's documented reach
- Kärcher documents no separate safety-tether or anchor system for this model, so a true high-rise installation falls outside the reach the 5-meter power cord provides.
- Leaded, heavily textured, or decorative glass
- Continuous suction contact from the cleaning pad assumes smooth flat glass; Kärcher's documented mechanism is not built for leaded or heavily textured panes.
- Panes smaller than the documented minimum size
- Kärcher specifies a 40 x 40 cm minimum working pane size; smaller windows fall outside the unit's documented operating range and are not a supported use case.
- Buyers wanting proven reliability before purchasing
- No independent reviews, owner reports, or field failure record exist yet for a product that only debuted at IFA 2026; that evidence gap is real.
What stays your job
The upkeep ownership hands back to you, whatever the autonomy level says.
HOBOT-S6 Pro
- After every use: Rinse dual mop pads; inspect suction gasket for mineral deposits or debris.
- Weekly: Soak mop pads in vinegar solution if hard-water spotting is visible; clean edge sensors.
- Monthly: Replace or deep-clean suction gasket; check cord for insulation damage or kinks.
- Every 3–6 months: Replace mop pads (~$25–$35 per pair); verify safety rope for frays.
- Annually: Inspect vacuum motor performance; if suction noticeably reduced, contact HOBOT support for service options.
Kärcher RCW 4
- After every use: Wipe down the cleaning pad and clear any trapped debris before storage.
- As needed: Refill the 150 mL detergent tank, checked against its fill-level indicator.
- Monthly: Inspect the 5-meter power cord and plug for fraying or damage.
- Monthly: Check the six pump-driven nozzles for mineral buildup or clogging.
- Every 3-6 months: Replace the cleaning pad once wiping leaves streaks or residue.
- As needed: Wipe the suction seal and glass-contact edge to maintain an even hold.
How much each of these is standing on.
Classifications rest on different depths of evidence. A pre-release assessment and a verified one are not the same kind of claim.
| Robot | Evidence status | Sources reviewed | Last assessed |
|---|---|---|---|
| HOBOT-S6 Pro | Pending | 1 | Aug 2026 |
| Kärcher RCW 4 | Pending | 1 | Sep 2026 |
Evidence status counts the sources behind a classification, not their kind. A high count can be maker documentation and price coverage, so read it as how much was reviewed rather than as independent testing. How we weigh evidence.
Keep going.
The full recordHOBOT-S6 ProSpecifications, evidence, the Fit Check in full, and every tracked change.
The full recordKärcher RCW 4Specifications, evidence, the Fit Check in full, and every tracked change.Robovations classifies robots; it does not rank them. Nothing on this page is a recommendation, and no manufacturer influences a classification or its placement here.
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