Kärcher RCW 4IIAssistedCompare

Released 2025.12Reassessed 2026.11.01Compare

Kärcher RCW 4

Name: Kärcher RCW 4
Brand: Kärcher

Six pump-driven nozzles spray detergent onto the cleaning pad while continuous suction holds the unit to the glass, with a 150 mL tank rated for about 1,100 sq ft and four automatic cleaning modes plus a manual option.

No list priceRetail price not tracked

Released 2025.12Reassessed 2026.11.01

Autonomy Ladder

Why Level II.

One five-rung scale, every category, from acting only on command to working unsupervised anywhere.

VGeneralized AutonomyAny task, any setting. No consumer robot has reached it.
IVEnvironmental AutonomyCopes with everyday clutter and frees itself, shown by independent testing.
IIIConditional AutonomyFinishes whole jobs in familiar spaces; struggles at the edges.
To reach Level IIIMost sessions finish without intervention. Rescue is occasional, not routine.
IIAssisted AutonomyThis robot

Kärcher RCW 4 runs preset routines on its own, and the owner is its recovery system.

Navigation and control

Systematic navigation with four corner sensors for frame, object and edge detection (frameless glass)
Why this level
- Kärcher's own documentation describes a corded design with four automatic cleaning modes and one manual mode, but the unit still must be lifted, positioned, and started separately on each pane, with a 40-minute backup battery holding suction during a power outage rather than resuming or finishing the job on its own.
- That per-pane manual setup keeps it at Level II.
Autonomy dimension 35 / 100 · 5 independent sources reviewed, 3 from the maker
IManual AutomationOne action on command; no independent operation.

How we assign a level →

Behind the classification

Sources on file.

Verified5 independent sources reviewed, 3 from the maker

Five or more independent sources reviewed. The word says how much we read. It is not a grade.

Independent sources reviewed5

Press & video reviews1 source

Independent German hands-on test of the base RCW 4: cleaning quality, suction hold, navigation and setup effort

Kärcher RCW 4 Fensterputzroboter im TestGeizhals

Monitoring record4 sources

Sources behind the tracker entries following this robot.

From the maker, reviewed3

Manufacturer documentation1 source

Kärcher's own RCW 4 product page: cleaning mechanism, suction, tank capacity and safety specs

Kärcher RCW 4 product pageKärcher

Specification sources2 sources

Pages the published specifications were read from.

s1.kaercher-media.coms1.kaercher-media.com
d1y4tv7o00gnfq.cloudfront.netd1y4tv7o00gnfq.cloudfront.net

Also monitored, nothing listed yet

Longitudinal signal

Long-term owner and field-failure record for the base RCW 4 still accumulating; early retail ratings mix in the Extra variant

How we evaluate evidence →

Human Readiness

Ready Now.

One question: what does buying this robot today walk you into? The state is computed from the record, and recomputed daily.

How it is sold: import only.

Ready NowThis robot

Kärcher RCW 4 is on sale, assessed, and nothing on its record argues for waiting.
How this was derived
- Purchasable, but through import channels rather than ordinary US retail.
- Shipping past the first-90-day ownership window with a published assessment, no documented issues on record, and no announced successor.
Notes on the record
- Announced at IFA 2025 and available in Europe from December 2025 at a 249.99 EUR list price; German and Spanish retailers have listed both models through 2026, with no US retail listing found.
- This record covers the base RCW 4, distinct from the higher-tier RCW 4 Extra variant.
On the record
- Shipping since December 2025 · 11 months on the market
- No successor announced
- 5 independent sources reviewed, 3 from the maker
What would move it
A documented problem, an announced successor, or a withdrawn listing moves it out; the rating recomputes daily.
New to MarketOn sale under 90 days; the ownership record is still forming.
WaitA successor is announced and has not shipped; re-read the decision when it arrives.
Known IssuesDocumented problems stand on the record; read the case before buying.

How we assess readiness →

Robovations Score

How this number was reached

53of 100

LimitedAt or above 11% of the 455 robots we scoreand 29% of the 24 scored robot window cleaners

DeficientLimitedCapableStrongExemplary

What moved itpoints gained or lost against a typical robot

Held back by

Software stability33−4.5
Task completion50−3.5
Routine maintenance48−2.4

Capability40% of the score56What it does without you.

Task completion16% of the score50

Evidence

Independent hands-on testing of the base RCW 4 (window cleaner) found it finishes a pane streak-free only when the glass starts fairly clean; on moderately or heavily soiled windows it leaves streaks unless the pane is pre-cleaned, and a person repositions it between panes.

Coverage and navigation10% of the score70

Evidence

Independent testing reported the four corner sensors reliably guided the unit across the whole pane and the square body reached every corner; coverage is re-established for each pane, which a window cleaner does by design.

Edge-case recovery10% of the score55

Evidence

Across an independent test the suction seal never slipped or let the unit fall on flat glass; on a power loss the backup battery holds position for up to 40 minutes rather than resuming the job, so a person restarts it.

Operating envelope4% of the score50

Evidence

Independent testing confirmed a dependable hold on smooth flat glass but noted the surface must be even or the seal can break, and results degrade on heavily soiled panes; minimum pane size is 15.7 × 15.7 in.

Dependability40% of the score52Whether it keeps doing it.

Field failure rate16% of the score68

Evidence

An independent hands-on test of the base RCW 4 documented no fall, stall, or job-stopping failure on flat glass, and roughly ten months on sale in Europe have surfaced no recall or systemic defect; the field record is still limited to a single test.

Software stability14% of the score33

Evidence

Kärcher's own materials name only onboard automatic and manual cleaning modes; no wifi, companion app, or firmware update channel is documented, which is a configuration fact rather than an absence of evidence.

Support longevity10% of the score52

Evidence

Kärcher lists replacement cleaning pads and RM 503 detergent as orderable parts and the standard consumer warranty applies, but no model-specific commitment on spare-parts availability or long-term support is published for the RCW 4.

Ownership burden20% of the score50What it asks of you.

Routine maintenance12% of the score48

Evidence

The unit must be moved, plugged in, and started separately for each pane, and the 150 mL detergent tank is refilled roughly every 1,100 sq ft; independent testing confirmed setup takes under five minutes but a person repositions it between windows.

Consumables8% of the score54

Evidence

Consumables are RM 503 detergent refills for the 150 mL tank and the replaceable cleaning pad; Kärcher does not publish a pad-replacement interval or price (priced by the consumables engine).

middle half of the databaseits medianthis robot

Reported, not scoredneither measures how well the robot works

Five-year costNot costed

List price is 249.99 EUR, with German retail near 248 EUR; the RCW 4 sells in Europe and not through US retail, so a five-year US cost is not estimated. Upper-mid tier among window-cleaning robots.

Data postureLocal

Core function needs no account and no network.

What leaves the homeDocumented

Kärcher's documentation for the RCW 4 does not describe a companion app, user account, or cloud data transmission; no wireless connectivity is documented for this model.

Read the full methodology →

FIT CHECK

Will the Kärcher RCW 4 work on your windows?

Describe your windows using the controls. Each choice reads the spec sheet for you, flagging where the Kärcher RCW 4 is built for your space and where it isn’t.

Window style

Frame style

Building height

Power preference

See every window cleaner suited to these conditions

A classification of fit for the conditions you set, not a recommendation. Verdicts describe engineering design intent, not test results.

OWNERSHIP

Living with it.

Independent testing found a dependable suction hold but streaks on anything past a lightly soiled pane.

Unprovenowner-reported arc

The record so far

A single independent hands-on test reports the vacuum seal never slipped on flat glass and the corner sensors guided it reliably across a pane, but it left streaks on moderately soiled windows without a manual pre-clean. No long-term field record exists yet.

What goes wrong3 documented · 0 self-recover

Common

Streaks on soiled glassResidue left on dirtier panes

Owner fixPre-clean the pane before starting a runper Independent test, 2026

Occasional

Fall risk on uneven glassSuction seal can break on non-flat surfaces

Owner fixUse only on smooth, flat panesper Independent test, 2026

Rare

Power outage halts the jobCleaning stops; battery only holds grip

Owner fixRestart the cycle once mains power returnsper Manufacturer spec, 2026

Upkeep routine

Each useEvery cycle

Wipe down the cleaning and clear any trapped debris before storage.

Monthly12×/yr

Inspect the 5-meter power cord and plug for fraying or damage.

Check the six -driven nozzles for mineral buildup or clogging.

Seasonal4×/yr

Replace the cleaning once wiping leaves streaks or residue.

As neededno fixed schedule

Refill the 150 mL detergent tank, checked against its fill-level indicator.

Wipe the seal and glass-contact edge to maintain an even hold.

Safety notes2 cautions · 2 notes

CautionBackup battery holds suction only about 40 minutes if mains power cuts out mid-cycle.
CautionCorded operation near glass and waterMains-powered operation combined with a wet cleaning pad calls for care around the power cord and outlet.
Detergent spray near old framesPump-driven nozzles spray detergent directly onto the pad, which may affect delicate or aged frame finishes.
Minimum pane sizePanes smaller than 15.7 × 15.7 in fall outside the documented operating range.

SPECIFICATION

The full spec sheet.

Manufacturer-published figures, measured against every robot window cleaner we track.

Dimensional drawing

Key specificationsManufacturer-publishedSources: Product page

FootprintThe width, depth and height of the robot itself, without its dock.: 10.1 × 10.4 in, 2.8 in tall
WeightThe robot alone, without its dock, as the maker states it.: 3.3 lbs
BatteryStored energy in watt-hours; a larger pack runs longer, not harder.: 10 Wh · Li-ion•
SuctionAir pressure the fan produces at the intake, in pascals, measured the maker's own way.: 3,000 Pa standard; up to 5,000 Pa max
Cleaning speed: Approx. 2.5 min per square meter
Min pane size: 15.7 x 15.7 in

Where it lands · position among 27 robot window cleanersThis robotMedianTypical range

NoiseLoudness at the maker's stated distance, in decibels; ten more decibels reads as about twice as loud.62dB

62 dB75 dB

Bottom of range

WeightThe robot alone, without its dock, as the maker states it.3.3lbs

2.02 lbs4.8 lbs

Near median

Position shows where the figure sits across the tracked category, not a quality judgment.

Official referencesProduct page

RECORD

How the assessment has moved.

Every announcement, release and reassessment behind the current classification.

Coming soon

Just launched

Active updates

Settled

Discontinued

Nov 2026 · AssessmentRecord status: Provisional → Verified
Oct 2026 · AssessmentReadiness assessed as Ready Now
Oct 2026 · AssessmentRobovations Score recorded at 53 of 100
Sep 2026 · AssessmentReadiness assessed as New to Market
May 2026 · ReleaseWindow cleaning robot goes on sale in Spain at 269.95 euros
Sep 2025 · AnnouncementKärcher unveils RCW 4 square window cleaning robot for frameless glass at IFA 2025

Questions

What people actually ask.

6 answered

OperationDoes the Kärcher RCW 4 need to stay plugged in the whole time it's cleaning?

Yes. It runs on a 5-meter mains power cord with no cordless or battery-only mode, so it needs a nearby outlet for every session.

OperationHow much glass can the RCW 4 clean before the detergent tank needs a refill?

Kärcher rates the 150 mL tank, which carries a fill-level indicator, for about 1,100 sq ft of cleaning per fill at a stated cleaning speed of roughly 2.5 minutes per square meter.

OperationWhat do the RCW 4's four automatic cleaning modes actually change?

Kärcher’s product page names four automatic modes plus one manual mode but does not spell out how the automatic modes differ; independent testing describes the overall cleaning pattern rather than distinguishing one automatic mode from another.

OperationWhat happens to the Kärcher RCW 4 if the power goes out mid-clean?

An onboard 0.65 Ah, 14.8V backup battery holds suction for up to 40 minutes, keeping the unit on the glass rather than letting it fall, per Kärcher’s own documentation.

OperationIs the Kärcher RCW 4 the same as the RCW 4 Extra?

No. The Extra is a separate, higher-tier variant in Kärcher’s lineup; this record covers the base RCW 4 only, and specs should not be assumed to carry over between the two.

OperationWhat is the smallest window the RCW 4 can clean?

Kärcher specifies a minimum pane size of 15.7 × 15.7 in (about 15.7 x 15.7 in); panes smaller than that fall outside the documented operating range.

Cite & Embed

Reference the Kärcher RCW 4 classification.

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Citation

Robovations. "Kärcher RCW 4: Autonomy Level II (Assisted Autonomy)." Autonomy Ladder™, assessed November 2026. https://robovations.com/robots/karcher-rcw-4/

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Where to next

Three ways to keep going.

For evaluators

Compare with a peer.

See the Kärcher RCW 4 and Kärcher RCW 2 side by side: autonomy level, Robovations Score, readiness, and price. Classification, not a verdict.

See the full comparison

Or compare with Ecovacs Winbot W2S Pro Omni, Tosima W5 Window Cleaning Robot, Gladwell Gecko.

For browsers

See every Level II.

Every robot we’ve classified at assisted autonomy. Sorted by readiness, score, and price. Filter by category, manufacturer, or release date.

Browse every Level II robot

Updated weekly with new entries and reclassifications.

Kärcher RCW 4

Will the Kärcher RCW 4 work on your windows?

Living with it.

The full spec sheet.

How the assessment has moved.

What people actually ask.

Other robot window cleaners we have classified.

Kärcher RCW 2

Ecovacs Winbot W2S Pro Omni

Tosima W5 Window Cleaning Robot

Gladwell Gecko

Reference the Kärcher RCW 4 classification.

Three ways to keep going.

Get the next reassessment.

Compare with a peer.

See every Level II.