388
2 independent reviewsRead the findings →An older HOBOT window robot with two spinning pads and a fine water mist. It suits big panes or upstairs windows you can't safely reach, leaving them streak-free. It's slow, loud and tied to a socket, though, and misses corners.
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What reviewers found
Two home tests from 2021, both in Australia. GadgetGuy ran it over five large bi-fold door panels at a coastal home and called it the best window robot it had tested. iTWire used it on upstairs windows and liked it with more reservations: it was loud, slow and couldn't always reach the edges. Both had bits of edge or corner left over, and both had to move it between panes. Owners on RobotObzor owners like its automatic spraying on the outside of high-rise flat windows but mention corners and occasional streaks. The two tests disagree on frameless glass.
GadgetGuy, hands-on · iTWire, hands-on, May 2021
Cleaning result
Mixed resultsGadgetGuy got streak-free glass with a dry pass then a wet one, even on salt-sprayed doors, but small corner patches stayed dirty. iTWire found it can't always reach the edges and may need two runs, ideally on warm, dry days to limit streaks.
Safety
Mixed resultsBoth found the grip strong: GadgetGuy said it stuck like glue, and iTWire saw it cling on when unplugged. But iTWire found the power connector pulled apart easily and had nowhere to tie the safety rope.
Surfaces it suits
Mixed resultsGadgetGuy used it on outside panes tilted to about 45 degrees but found indoor angled glass difficult, and both GadgetGuy and iTWire say it can't clean frameless glass. Assume it needs a frame.
Ease of use
Mixed resultsGadgetGuy found setup straightforward and used very little fluid, but had to move it every six minutes or so. iTWire found the manual terse, expects most people will need an extension lead, and found it at least twice as slow as cleaning by hand.
Noise
Not enough evidenceOnly iTWire commented on noise, finding the suction fans loud enough to scare the family cat. No second review we use assessed it.
Value
Mixed resultsGadgetGuy gave it an unreserved recommendation at its Australian price, while iTWire liked it but warned the price may put people off.
Verdicts come from independent, hands-on, finished reviews. An area needs at least two of them before we say more than “Not enough evidence”. We don't score robots ourselves. How this works
Clear glass, if you do two passes
GadgetGuy ran a dry pass to lift dust and grime, then a wet pass, and got streak-free glass it rated above cleaning by hand, even on salt-sprayed coastal doors. iTWire says you may need to run it twice, and notes HOBOT recommends warm, dry days to cut down on streaks and smears. Owners on RobotObzor owners were mostly happy with the finish, though one saw occasional streaks. Allow for two runs on each pane rather than one.
Corners and edges stay unfinished
Round pads can't fill a square corner. GadgetGuy found it cleaned everything bar a small part of the top and bottom corners, and iTWire says the way it moves means it can't always clean right to the edge. Owners on RobotObzor owners put up with the same gap. GadgetGuy also had to clean the frames and tracks separately. Keep a cloth handy for the corners and plan on doing the frames yourself.
Frameless glass: the testers disagree
GadgetGuy says pressure-change detection keeps it away from frameless edges. iTWire says it can't work on frameless windows, and didn't try it on its own frameless bathroom mirror. HOBOT's page doesn't answer it either way. Neither test shows it running on frameless glass, so if that's what you need to clean, assume it wants a frame and look at a model sold for frameless panes.
Slow, loud and tied to a socket
iTWire found it took at least twice as long as cleaning by hand, and its suction fans were loud enough to scare the cat. GadgetGuy timed about six minutes for each 1.37m² panel, close to HOBOT's claim, but that meant staying to move it on every six minutes. The cord reaches about 5m from a socket, per GadgetGuy, and iTWire expects most people will need an extension lead. The power connector also pulled apart with little tension in iTWire's test.
The safety rope needs an anchor
A 4.5m safety rope comes in the box. GadgetGuy calls it essential for outside windows on upper floors but optional indoors. iTWire couldn't find anywhere on its house to tie it, and half-jokingly suggests leaving something soft under the window. Unplugged, the robot clings to the glass but won't move, iTWire adds. Work out where the rope will go before you send it up an outside window.
Both tests date from 2021. Owner reports on RobotObzor are in Russian and aren't verified purchases.
Our take
Should you buy the 388?
Best for: Large windows cleaned regularly, with a socket nearby. Skip it if: Your windows are frameless.
Buy it if you have big panes or upstairs windows you can't safely reach, and you're happy to stay nearby and move it along. Skip it if your windows are small, frameless or far from a socket. The Ecovacs WINBOT W2S OMNI runs from a battery station and has three recent tests behind it, while HOBOT's own S7 Pro scrubs harder but was still streaky on dirtier glass.
The 388 is one of HOBOT's older window cleaners, with two round microfibre pads that spin as it works its way across the glass. It mists water ahead of itself through an ultrasonic sprayer and holds on with a suction fan. It runs from the mains, and HOBOT says a backup battery keeps it on the glass for 20 minutes if the power drops. The 368 is the same idea without the spray, and the newer S7 Pro swaps the spinning pads for ones that scrub back and forth.
The trade-offs are reach, corners and time. With a 4m cord it can't stray far from a socket, the round pads leave small triangles in the corners, and one tester found it took at least twice as long as cleaning by hand. The tests are from 2021, so check that current stock comes with the same accessories.
Before you buy
The questions people ask about this one
Will it work on frameless glass?
Probably not reliably. GadgetGuy says pressure-change detection keeps it away from frameless edges, but iTWire says it can't work on frameless windows. HOBOT's page mentions edge detection but doesn't promise frameless support, per the specifications. Assume it needs a frame.
What happens if the power cuts out?
HOBOT says a built-in backup battery keeps it on the glass for 20 minutes while an alarm sounds, per the specifications. iTWire confirms that when it's unplugged it clings to the window but won't carry on cleaning, and found the power connector pulls apart easily.
Does it leave streaks or edges?
Edges, yes: GadgetGuy had small triangles left in the corners, and iTWire says it can't always reach the edge. Streaks come down to technique. GadgetGuy got a streak-free finish with a dry pass then a wet one, while iTWire sometimes needed a second run.
Can I use it on upstairs outside windows?
Yes, with care. iTWire used it on second-storey windows without a ladder, and GadgetGuy says the 4.5m rope is essential outside. iTWire found nowhere on its house to tie the rope, so sort out your anchor point first.
How long does one window take?
HOBOT claims four minutes per square metre, per the specifications. GadgetGuy measured about six minutes for a 1.37m² panel, and around an hour for 13.7m² of glass. iTWire reckons it takes at least twice as long as a manual clean.
Alternatives
Other window-cleaning robots to compare.
WINBOT W2S OMNI
Why consider it: Its battery station means no socket by the window, and three recent tests found it cleans everyday dirt well and gets closer to the edges than most.
The compromise: Corners still aren't perfect, and you move it between panes and wash the pad yourself.
S7 Pro
Why consider it: HOBOT's newer model scrubs with two pads, and TechRadar found it spot on at detecting frameless edges.
The compromise: Both tests found streaks on dirtier glass, and it saves effort rather than time.
WINBOT mini 2
Why consider it: Compact enough for smaller panes, and a tester found it cleared fingerprints and dust and reached right to the frame.
The compromise: It's loud, slow on dried-on marks, and you'll stand beside it the whole time.
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 388?
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
- Robot My Life: HOBOT 388 review ↗
- Home Robot USA: How to Use HOBOT-388 Window Cleaning Robot with Ultrasonic Water Spray - Video Manual (ver.2) ↗
- Search YouTube for HOBOT 388 ↗Search results may include company demonstrations or similar models. Check the source and model name; a demonstration is not an independent performance test.