ECOVACS WINBOT W2S Omni vs W3 Omni

W2S Omni vs W3 Omni at a glance

Head to head

The best result in each row is marked, based on my testing and the manufacturer specs. Where the robots tie, both are marked.

The tally is a guide, not my verdict. How often you clean and how much you hate rinsing pads matters more than any single row.

What they share, and what they don’t

These two robots are closer than their names suggest. Both are square crawlers with 8,000 Pa of rated suction✕Suction in PaHow hard the robot presses itself to the glass, measured in pascals. More suction means a firmer grip on high and outside windows., and both use the same spinning TruEdge✕TruEdgeA small rotating scrubber at the robot’s edge that reaches into the strip along frames and corners, where a flat pad leaves a dirty line. scrubber, rated at up to 200 RPM.

Both run from a battery station or plugged in, both hold on when the battery runs low, and both are built for big, flat, rectangular glass.

The differences are in the station and the brain. The W3 Omni station washes the pad with Vortex Wash✕Vortex WashThe W3 Omni station’s pad-cleaning system. Sixteen high-pressure nozzles wash the pad in about a minute and send the dirty water to a separate tank., it navigates with WIN-SLAM 5.0 and it is rated for 130 minutes. The W2S Omni has the lighter 6-in-1 station, WIN-SLAM 4.0, 110 minutes and a dedicated Heavy-Duty mode.

Our tip: If you clean the same windows every week, weigh the station more than the robot, because that is where these two really differ.

Design, station and weight

The robots look almost identical on the glass. The stations do not.

The W2S Omni’s 6-in-1 station is a tall box that stores the robot, holds the solution, charges the battery and anchors the safety tether. It is heavy enough that I planned sessions room by room, but I could carry it up a flight of stairs without much complaint.

The W3 Omni’s station carries clean and dirty water tanks for pad washing, and the whole kit weighs close to 27 lb. It is weighted on purpose, with suction cups, so it makes a very solid anchor, but it is not something I wanted to lift onto a high shelf every week.

The W3 Omni’s station holds clean and dirty water for pad washing.

Kit weight

ECOVACS publishes the W3 figure; the W2S is my own judgment.

Setup and the first week

The W2S Omni took about 15 minutes out of the box, most of it on the ECOVACS HOME app and a firmware update. After that, sessions took about 3 minutes to start and 1 to 2 minutes to pack away.

The W3 Omni took about 20 minutes the first time, because there are tanks to fill and the washing system to prime. After that it was about 2 minutes per session.

Week one went slightly better on the W2S Omni, 7.4 against 7.2, because the W3 had more new habits to learn. By week two they were tied at 8.4.

Our tip: Update the firmware on both before the first clean, because an update that starts mid-session is a waste of a battery charge.

Suction and safety

With the same 8,000 Pa of suction, both robots felt equally planted on the glass. I never had either one come off.

The W3 Omni scored a little higher for safety, 9.3 against 9.0, because its weighted station, double-lock buckle and auto-tightening anti-fall cable made the anchor feel more foolproof. The W2S Omni uses a tether with a locking clip and a suction cup on the station.

Both return to their start point and hold on for up to 30 minutes when the battery runs low, with a voice alert. That beats a ladder, which the U.S. Consumer Product Safety Commission links to more than 164,000 emergency room-treated injuries a year.

How well they clean

On everyday dirt, these two are effectively a tie. Both scored 9.2 on dust and pollen and 9.0 on fingerprints and nose prints.

On rain and water spots, the W2S Omni scored 8.6 and the W3 Omni 8.2. The W2S has triple nozzles on both sides, and it seemed to wet the spots a little more evenly.

The bigger gap was on months of outside grime. The W2S Omni’s Heavy-Duty✕Heavy-Duty modeThe W2S Omni’s most intensive mode, with extra passes and more scrubbing for glass that has gone months without a clean. mode scored 8.0 in one pass, while the W3 Omni’s Intensive mode scored 7.4.

Months of outside grime, one pass

My scores out of 10, same street-side windows.

The W3 Omni closes that gap with a trick of its own. On neglected glass I ran Intensive, let the station wash the pad, then ran Fast, and the second pass with a clean pad cleared most of the haze.

On the W2S Omni, the equivalent is swapping to a spare pad by hand. It works just as well, but you are the one doing the swap.

Our tip: On neglected glass with the W3 Omni, run Intensive, let the station wash the pad and finish with Fast, because a clean pad on the second pass made the biggest difference.

The W2S Omni’s Heavy-Duty mode was the stronger one-pass cleaner on grimy glass.

Edges and corners

With the same TruEdge scrubber, the edges were nearly identical. Both scored 8.6 along the frames and 8.6 overall for edge coverage.

In the center of the glass, the W3 Omni scored 9.6 and the W2S Omni 9.5. In the inside corners, the W3 Omni edged ahead at 7.8 against 7.6, which I put down to its newer WIN-SLAM 5.0 route hugging the frame a little more closely.

On a sunny day, you would not pick one from the other by looking at the corners. Both leave a very small sliver that a quick wipe removes.

Inside corners

My scores out of 10.

Pad washing: the real difference

This is the reason the W3 Omni exists. After each window, the robot returns to the station and 16 high-pressure nozzles wash its pad in about a minute, sending the dirty water to a separate tank.

My hands-on cleanup with the W3 Omni dropped to about 1 minute per session. With the W2S Omni, rinsing pads at the sink took about 4 minutes, and cleaning by hand took about 20 minutes per room.

That sounds small, but it changed my habits. With the W3 Omni I ran the robot on a whim, because there was nothing waiting at the end. With the W2S I batched windows to save a rinse.

Hands-on cleanup per session

My own timings.

Pad care also matters for results on the W2S Omni. A damp, well wrung-out pad scored 9.0 on the same window where a soaking-wet pad scored 6.2, a pad reused from a dirty window 5.5 and a dry pad 4.8.

ECOVACS suggests replacing W3 pads about every 30 cycles. In my use, that stretched to about 40 cycles on light indoor glass and fell to about 20 on very dirty outside glass.

W2S Omni: same window, different pad

My scores out of 10.

Our tip: Swap to a spare pad halfway through a whole-house session on the W2S Omni, because a pad carried from a dirty window scored barely half of a fresh one.

Navigation, modes and controls

The W2S Omni navigates with WIN-SLAM 4.0 and the W3 Omni with WIN-SLAM 5.0, which ECOVACS says detects obstacles to within 1 mm. Both measured every rectangular pane correctly and returned to where they started.

The W2S Omni gives you Fast, Thorough, Deep, Heavy-Duty and Edge, plus app remote control. The W3 Omni has Fast, Intensive, Zone and Manual, with more options in the app.

I liked the W2S Omni’s extra modes for dirty glass. I liked the W3 Omni’s Zone mode for a single smudged patch on a big door.

Our tip: Use the W2S Omni’s Edge mode as a finishing pass on sliding doors, because handle-height fingerprints along the frame are what people notice first.

Battery and power

The W2S Omni is rated for about 110 minutes and up to about 65 m² in Fast mode. The W3 Omni is rated for up to 130 minutes.

In practice, 110 minutes covered my whole ground floor with charge to spare. The W3 Omni’s extra 20 minutes carried a full day of larger windows, including the pad-washing stops, without plugging in.

Both can run plugged in with no time limit. I did that on a long run of conservatory glass.

Rated battery

Manufacturer ratings.

Which windows suit each

Both robots were excellent on large picture windows and sliding glass doors, and both were fair on arched or unusually shaped glass.

The W2S Omni was very good on upper-floor outside windows and on a glass office partition with small joins. The W3 Omni was at its best on large windows that I would normally pay someone to clean, and on high outside glass that usually gets skipped.

Neither is the right tool for a few small, easy-to-reach windows. The setup takes longer than the clean.

Noise, pets and family life

Both robots make a steady fan hum, about like a hair dryer on low. You hear them clearly in the same room, and they fade one room away.

The W3 Omni adds a short burst of water noise when it washes the pad. It lasts about a minute and is quieter than the fan.

My cat sniffed the W3 Omni’s tether on day one. On both robots, I kept the rope tidy and along the wall, and closed the door on low panes when the dog was in the mood to chase moving things.

A whole-house cleaning day with each

In week four, I gave each robot the same day: inside and outside of the ground floor, the balcony doors and the upstairs windows I can reach.

With the W2S Omni, I prepared in about 3 minutes, swapped to a spare pad halfway, ran Heavy-Duty on the street side and rinsed pads at the end. The heavier station was the only thing that slowed me on the stairs.

With the W3 Omni, the robot came back to the station between windows to wash its pad, and my only job at the end was emptying the dirty-water tank. It was the easiest window day I have had.

Cleaning and maintaining them

On the W2S Omni, upkeep means rinsing pads after each session, wiping the edge sensors and underside after outside glass and checking the tether for fraying.

On the W3 Omni, the pads take care of themselves, but the tanks do not. I rinsed the dirty-water tank right after every session, because standing dirty water starts to smell.

For storage, I kept the W3 Omni with clean pads fitted and an empty dirty tank. The W2S Omni simply lives in its station.

Our tip: Rinse the W3 Omni’s dirty-water tank right after each session, because it is the one chore that gets unpleasant fast if you skip it.

Mistakes to avoid

Most weak results came from the same handful of habits. The last two rows apply mainly to the W3 Omni.

On water, it is worth knowing your tap. The U.S. Geological Survey classes water above 120 mg/L of calcium carbonate as hard, and those minerals are what leave spots on glass and slowly clog fine spray nozzles.

My four weeks, week by week

Week one: inside glass and learning. The W2S Omni scored 7.4 and the W3 Omni 7.2, mostly because the W3 had more routines to learn.

Week two: outside glass. Both scored 8.4. The W2S Omni impressed me with Heavy-Duty, and the W3 Omni with how little I had to do afterward.

Week three: odd and dirty glass. The W2S Omni reached 8.7 on a partition and small windows, and the W3 Omni 8.8 on large windows.

Week four: routine use. The W2S Omni finished at 8.9 and the W3 Omni at 9.0.

Week four satisfaction

My weekly scores out of 10.

Real-life scenarios

These are the moments during testing where one robot clearly pulled ahead.

For regular cleaning with almost no cleanup, the W3 Omni is hard to beat.

My scorecard

These are my own scores out of 10, from my single reviews of each robot after four weeks of daily use.

Overall scores

My overall editorial scores out of 10.

The W3 Omni wins overall because it cleans as well as the W2S Omni on most glass and asks far less of you afterward. The W2S Omni is the stronger choice for glass that goes months between cleans.

Which one should you buy?

Start with how often you clean and how much the sink bothers you.

If you clean large windows every week or two, buy the W3 Omni, because pad washing changes the whole routine. If your outside glass goes months between cleans, or you climb stairs with the station, the W2S Omni is the better buy.

For everything I found, see my W2S Omni review and W3 Omni review, or my comparison of all four Winbot station robots.

Living with them long term

The W2S Omni needs pads rinsed every session and the tether checked. The W3 Omni needs its dirty tank emptied and pads replaced about every 30 cycles.

What I would change: pad washing on the W2S Omni, a lighter station and no parking mark on the W3 Omni.

For most frequent window cleaners, the W3 Omni is the one to get.

W2S Omni vs W3 Omni specifications

From manufacturer specifications and my own testing.

How I tested and compared them

I used each robot as my main window cleaner for four weeks, on inside windows, sliding doors, balcony glass and neglected street-side windows. A second HouseholdMe tester shared the robots, and we wrote the notes together.

I scored both on the same windows with the same solution, and timed every setup, session and cleanup.

I then checked my notes against ECOVACS’ specifications and owner documentation.

• Cleaning: dust, fingerprints, rain spots and months of outside grime.
• Edges: frames, inside corners and frameless edges.
• Safety: suction hold, power-loss behavior and the safety rope.
• Ownership: setup, pads, refills, storage and noise.