Robot Vacuum S40C
Limited evidenceRead the findings →The entry point to Xiaomi's S40 range, a mapping robot with a damp cloth for light wiping. It keeps everyday dust down in a small, tidy home. It's weak on carpet and hair, and you do all the upkeep.
See the alternatives below, or switch market.
Where it sits in Xiaomi’s range
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What we know
Teszt Plussz bought both the S40C and the S40 and compared them in an 80m² flat. The S40C made the flat cleaner day to day and collected cat litter, but it left dirt and hair in carpet and tangled long hair round its brushes. It also bumped into things, and the mop only gave a light wipe. The tester preferred the S40. This is the only completed independent test we link here.
Teszt Plussz, hands-on, Feb 2026
Fine for dust, weak on carpet
Teszt Plussz found the flat felt noticeably cleaner after runs and cat litter was picked up well, but it often left dirt and dust behind, especially on carpet. In the tester's view, halving the suction compared with the S40 was a mistake. Think of the S40C as a way to keep hard floors tidy between proper vacuums, not as a carpet cleaner.
Long hair ends up on the brush
Despite Xiaomi's tangle-free claim, Teszt Plussz found longer hair wrapped round the main brush rather than ending up in the 520ml bin, and the plain side brush tangled too. Hair and cat fur were also left behind on carpet. If anyone at home has long hair, expect to cut it off the brush regularly.
Maps fast, bumps often
Teszt Plussz saw it map the 80m² flat in six or seven minutes and follow a neat route close to the walls. It knocked into furniture often, and not only while learning the flat, and it didn't split the rooms properly or spot the terrace. It stopped at stairs and crossed 2cm thresholds without trouble. Expect to tidy up the map by hand.
The cloth is a light wipe
Teszt Plussz describes the mopping as damp wiping rather than real mopping. It's fine for picking up fine dust so less of it floats around, and it was frugal with water, leaving more than half the tank after a run on the middle setting. The tester didn't try stains, because it isn't built for them.
Teszt Plussz reviewed in Hungarian; its findings are summarised here in English. This page covers the S40C, not the S40 or S40 Pro.
Our take
Should you buy the Robot Vacuum S40C?
Best for: Small, tidy flats needing regular vacuuming. Skip it if: You have a pet that sheds heavily or lots of long hair.
The S40C suits basic hard-floor upkeep in a small, tidy home if its price is low. Teszt Plussz preferred the S40, especially on carpet, so compare current offers for both. S40 reviewers also reported hair tangles. Either model leaves you with manual brush cleaning, bin emptying and mop washing.
The S40C is the entry point to Xiaomi's S40 range. It looks almost identical to the S40 and maps your home with the same kind of spinning laser, but it has half the suction and a much smaller battery. Like the S40, it drags a damp cloth for wiping and sits on a base that only charges.
So you do the upkeep: empty the bin, refill the water tank, wash the cloth and clear hair from the brushes. It won't lift the cloth for rugs, so you tell it where they are in the app.
The S40 and S40 Pro are different robots with their own pages and their own tests, so don't mix up their reviews with this one.
Before you buy
The questions people ask about this one
S40C or S40?
The S40, if you can stretch to it. It has double the claimed suction and a bigger battery, per the specifications, and Teszt Plussz, which bought both, found the S40 clearly better, especially on carpet.
How often do I have to empty or refill anything?
Every few runs. The base only charges, so you empty the 520ml bin and refill the 260ml tank yourself, per the specifications. Teszt Plussz found water use frugal, but the cloth still needs washing after each mopping run.
Can it cross rugs and raised thresholds between rooms?
It's claimed to climb 2cm steps with a dry cloth, per the specifications, and Teszt Plussz had no trouble with 2cm thresholds. It left dirt and hair in carpet, and it can't lift the cloth, so mark rugs in the app before mopping.
Is it loud?
Not much. Teszt Plussz found it pleasingly quiet, even in Turbo. The noise it does make comes from bumping furniture and rattling over tile grout lines.
Alternatives
Other robot vacuums to compare.
Q7 M5 / M5+
Why consider it: Another low-cost mapping robot that vacuums and lifts pet hair far better than its price suggests.
The compromise: It bumps into clutter too, and its charge-only dock means you empty the bin yourself.
RV30 Max Plus
Why consider it: A low-cost robot with laser mapping and a compact dock that empties the bin.
The compromise: Fine grit and sticky spills beat it, and mopping is only a clip-on pad.
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 Robot Vacuum S40C?
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
- Tothepoint Tutorials2: Xiaomi Robot Vacuum S40C Review - IMPORTANT Things To Know ↗
- Syntech Distribution: XIAOMI Robot Vacuum Cleaner S40C ↗
- Search YouTube for Xiaomi Robot Vacuum S40C ↗Search results may include company demonstrations or similar models. Check the source and model name; a demonstration is not an independent performance test.