A window robot holds itself to the glass with suction and wipes in a pattern while you do something else. For outside glass or anything up high, two features matter most: a safety rope and a backup battery that keeps it on the glass if the power cuts.
Our picks at a glance
From published specs and our sizing rules. Not lab tested.
- 1
Safety plus speed
HOBOT-2S Dual Ultrasonic Spray Window Robot
Check price on AmazonPaid link
- 2
Most suction
ECOVACS WINBOT W2S PRO Triple Spray Window Robot
10,000 Pa suction
Check price on AmazonPaid link
- 3
Budget
Mamibot W120-DP 4-Spray Window Robot
7,000 Pa suction
Check price on AmazonPaid link
Auto spray saves you wetting the pad, and frameless support lets it work on shower doors and glass railings without an edge to stop it.
Top picks, and why
HOBOT-2S Dual Ultrasonic Spray Window Robot
- safety rope
- 20 min backup battery
- auto spray
- frameless glass
+1 moreFewer
- 4.4 sq ft/min
Safety rope, 20 minute backup battery, dual ultrasonic spray and frameless glass support. $250 to $500.
- Dual replaceable ultrasonic spray tanks
- UPS holds it on the glass 20 minutes after a power cut
- Cleans about 1 square meter in 2.4 minutes
- Runs on the power cord only
- Needs at least 15 x 15 inches of glass, no rounded frames
$250 to $500, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
ECOVACS WINBOT W2S PRO Triple Spray Window Robot
- 10,000 Pa
- safety rope
- auto spray
- frameless glass
10,000 Pa, safety tether, triple spray and frameless glass. $250 to $500.
- 10,000 Pa suction with 10-stage fall protection
- 4.1 fl oz tank covers up to 807 sq ft per fill
- Six modes including Edge, Deep and Zone
- No self-cleaning station; pads are washed by hand
- Safety tether must be attached on every run
$250 to $500, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
Mamibot W120-DP 4-Spray Window Robot
- 7,000 Pa
- safety rope
- auto spray
7,000 Pa with a safety rope and four spray nozzles. $100 to $250.
- 7,000 Pa variable suction with edge sensors
- Slim 2.7 inch body reaches narrow frames
- Remote plus app with scheduling
- Frameless glass needs a support edge of at least 3 mm
- No backup battery hold time stated
$100 to $250, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
Compare every pick
Paid links: we earn a commission if you buy, at no cost to you. Amazon prices change often, so we show a range and link to the live price.
Outside and high windows
Buy a rope and a backup battery for any glass where a fall would hurt someone or something.
HUTT 10 Premium Round-Square Dual Pad Window Robot
- 6,500 Pa
- safety rope
- 30 min backup battery
- auto spray
6,500 Pa, safety rope and a 30 minute backup battery, dual spray. $250 to $500.
- UPS keeps adhesion up to 30 minutes after a power loss
- Safety rope rated to 220 kg
- 80 ml tank covers up to 646 sq ft per refill
- Square pads must stay dry or traction drops
- 6,500 Pa suction is below the 8,000 Pa and up models
$250 to $500, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
HOBOT-SP10 iScraper Spray and Squeegee Window Robot
- 6,000 Pa
- safety rope
- 20 min backup battery
- auto spray
+1 moreFewer
- frameless glass
6,000 Pa, rope, 20 minute backup, dual spray and scrapers, frameless. $250 to $500.
- Dual scrapers remove leftover water behind the cloth
- UPS holds suction 20 minutes after a power loss
- Works on sloped glass such as greenhouse roofs and solar panels
- 6,000 Pa suction is below the 10,000 Pa ECOVACS models
- Scrapers and nozzles are wear parts to replace
$250 to $500, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
Mamibot EcoHomely W150-DP 8-Nozzle Spray Window Robot
- safety rope
- 20 min backup battery
- auto spray
- frameless glass
Rope, 20 minute backup, eight nozzles, frameless glass. $250 to $500.
- Backup battery holds it 20 to 30 minutes after a power loss
- 4 m safety rope rated to 135 kg
- 110 ml tank, sprays only at frames and turns
- Needs glass at least 5 mm thick and 60 x 60 cm
- Suction in Pa is not published
$250 to $500, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
Indoor glass and shower doors
Frameless support matters on shower doors and glass railings, where there is no frame to tell the robot where the edge is.
MOVA N1 Compact Dual Spray Window Robot
- 8,000 Pa
- auto spray
- frameless glass
Dual spray and frameless glass support. $100 to $250.
- 8,000 Pa suction with 12-level safety protection
- Slim 59 mm profile fits narrow panes
- Six app modes including Edge and Spot
- Backup battery hold time is not published
- Small body means more passes on large glass
$100 to $250, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
HOBOT-298 Ultrasonic Spray Window Robot
- safety rope
- 20 min backup battery
- auto spray
- frameless glass
+1 moreFewer
- 4.4 sq ft/min
Rope, 20 minute backup, ultrasonic spray, frameless. $100 to $250.
- UPS holds it on the glass 20 minutes after a power cut
- Cleans about 1 square meter in 2.4 minutes
- Works on small panes from 13 x 13 inches
- Single spray tank, versus two on the HOBOT-2S
- Runs on the power cord only
$100 to $250, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
The bottom line
From published specs and our sizing rules. Not lab tested.
- 1
Safety plus speed
HOBOT-2S Dual Ultrasonic Spray Window Robot
Check price on AmazonPaid link
- 2
Most suction
ECOVACS WINBOT W2S PRO Triple Spray Window Robot
10,000 Pa suction
Check price on AmazonPaid link
- 3
Budget
Mamibot W120-DP 4-Spray Window Robot
7,000 Pa suction
Check price on AmazonPaid link
Frequently asked questions
Do window cleaning robots work on the outside of windows?
Yes, they hold on with suction. For outside or upper floor glass, use one with a safety rope and a backup battery that keeps it attached if power drops.
Do window robots work on frameless glass?
Only models that say so. Frameless detection lets them find the edge of a shower door or railing; others rely on a frame to stop.
How do window cleaning robots stay on the glass?
A vacuum pump pulls the robot against the glass, rated from 5,600 Pa on the KADSKAN to 10,000 Pa on the ECOVACS WINBOT W2S PRO. The pump needs power the whole time, which is why most run on a cord and carry a safety rope.
What happens if the power goes out while a window robot is on the glass?
A backup battery keeps the suction running long enough to take it down. The HOBOT models hold for 20 minutes, the Mamibot W150-DP for 20 to 30 minutes and the HUTT 10 Premium for up to 30 minutes. The safety rope is the second line of defense, rated to 220 kg on the HUTT and 135 kg on the Mamibot W150-DP.
How long does a window robot take to clean a window?
A few minutes per pane. HOBOT rates its 2S and 298 at about 1 square meter in 2.4 minutes, or 4.4 sq ft per minute, so a 3 by 5 ft pane (15 sq ft) takes about 3.4 minutes per side. ECOVACS rates the WINBOT W3 OMNI at under 2 minutes per square meter in Fast mode.
Do window cleaning robots work on small windows?
Only above each model's minimum glass size. The HOBOT-298 works on panes from 13 by 13 inches, the HOBOT-2S needs 15 by 15 inches, the HUTT 10 needs 30 by 30 cm, and the Mamibot W150-DP needs 60 by 60 cm and glass at least 5 mm thick. The MOVA N1 has a compact 215 mm body for narrow panes.
Can a window robot clean skylights or solar panels?
Most are built for vertical glass. The HOBOT-SP10 is the exception in our list: HOBOT says it works on reclined panes from 7 to 100 degrees, including greenhouse roofs and solar panels.
How much glass does a window robot clean per tank of water?
ECOVACS rates the WINBOT W2S PRO's 4.1 fl oz tank for up to 807 sq ft per fill, and HUTT rates the 10 Premium's 80 ml tank for up to 646 sq ft. The Mamibot W150-DP holds 110 ml and sprays only at frames and turns.
Why does my window robot leave streaks?
Usually a dirty or overly wet pad. Start each run with a clean pad, and on models with a dry polishing pad, like the square pad on the HUTT 10 Premium, keep that pad dry or traction and finish suffer. The HOBOT-SP10 adds dual scrapers that squeegee off water left behind the cloth.
Do window cleaning robots clean the edges and corners?
They follow the frame, but a robot cannot reach fully into a corner, so expect to wipe the last bit by hand. The ECOVACS WINBOT W2S PRO uses four edge brushes along frames and has an Edge mode, and several models offer edge or spot modes in their app.
8 products are linked on this page. We have not lab-tested these products; picks are based on published specifications and our sizing rules. Amazon prices change, so we show a range and link to the live price. See our disclosure.
Size it for your home
Marcus Reed
Founder and Editor, CrunchYourDollars
Marcus Reed builds the sizing tools on CrunchYourDollars. He is a software engineer with a long-running PC hardware and power supply habit, which is where the watts, watt-hours and surge math on this site comes from. Product specs are pulled from manufacturer data sheets, electricity rates from the U.S. Energy Information Administration, and water chemistry rules from the Water Quality Association. He is not a licensed electrician or plumber: the tools show the math and the matching models so you can make the call, and anything involving your electrical panel should be checked by a licensed pro.
More about CrunchYourDollars and how we researchGet notified when we add tools
An occasional email when a new sizing tool goes live or the product database is refreshed. No spam, unsubscribe anytime.