This busy mom tested a window-cleaning robot: “My life (or at least the way I clean windows) was transformed”

Does it really clean windows thoroughly? What if it falls? For years, I’d hoped window-cleaning robots would become advanced and affordable enough so I could finally ditch my least favorite household chore. Still, I was skeptical about whether the gadget could really do the job. And I didn’t want to make an expensive purchase only to find out it was as pointless as a cotton candy machine.

My life (or at least the way I clean windows) was transformed when I borrowed a window-cleaning robot to test at home. Inside the white charging case was a simple-looking box with just one button. You adjust the wash settings via a smartphone app. The device is a Winbot W2 Pro Omni model. The kids nicknamed it Onni.

The hardest part, at first, was letting Onni loose. One press of the button, and it latched onto the glass, making a soft sound. For a moment, I stayed close by, ready to catch it if needed. Then my spouse and I stood there slack-jawed, watching Onni climb every which way across the window. It really stayed in place, and the glass got clean all on its own!

A voice prompt lets you know when the cleaning is done and it’s safe to detach Onni from the window. It also alerts you if the device needs charging. On a single charge, Onni can clean about ten large windows on the basic setting. The power wash mode uses more battery.

What on earth? Even the cat looks baffled. The window-cleaning robot uses its motor to suction itself onto the window. It draws power from the charging case through a cable.

I checked the results in sunlight. It’s surprisingly good—good enough for me. Onni leaves fewer streaks than I do when I clean by hand, and there aren’t any drips. There’s just a half-centimeter strip near the window frames that Onni can’t quite reach. Of course, if there’s pine resin or other stubborn grime that needs scraping, the robot can’t handle that any better than a normal hand-wash.

It’s a good idea to rinse the Velcro-attached mop pad after each window. Avoid cleaning in direct sunlight or windy conditions so you don’t end up with streaks. For outdoor surfaces, you’ll want to use power wash mode. And if you’re not satisfied with the result, you can simply run it again.

As always, it's wise to read the manual. The robot cleaner can struggle to stay attached to surfaces with stickers, gaps, or unevenness. It’s not intended for cleaning glass under three millimeters thick or mirrors under four. My sauna’s glass wall and door, as well as our balcony’s glass railing, are thicker than that. The device is about eight centimeters thick and nearly 27 centimeters across, so this model won’t fit into tight spaces or narrow windows.

The window-cleaning robot’s microfiber pad is moistened with water, squeezed until damp, and attached to the device. As it moves across the glass, the robot sprays a cleaning solution ahead of itself.

The instructions advise checking the glass for “small particles” before washing and removing them so the glass doesn’t get scratched. That’s a good call. Our street-facing windows collect a fair bit of grit, so a quick wipe with a mop is wise beforehand. My spouse didn’t read the manual and ended up with a few hairline scratches on one window, which, thankfully, only show at certain angles in bright sunlight. Another downside is that, on top of the purchase cost, you need to keep buying the manufacturer’s recommended cleaning solution. We go through about one 25-euro bottle when washing all our windows.

While the robot cleans the windows, you can do other tasks, but a human is still needed: sometimes the finishing spot leaves a mark that can be wiped off with a cleaning cloth. The mop pad needs rinsing and reattaching after each window, and you have to move the device to the next window—which at our house occasionally involves sturdy ladders, but for the first time ever, we can properly wash all the upper windows. Sometimes you’ll need to add more cleaning solution, and that’s about it.

It turned out we didn’t want to give up Onni at all. We ended up sharing it with other houses on our street, since it’s hardly necessary to wash windows every day. Our neighbor, who has windows 5.5 meters tall, was especially thrilled. That’s Onni’s maximum reach, determined by the length of the cable.

For this article, we tested the Ecovacs Winbot W2 Pro Omni window-cleaning robot (recommended price €599) at home.