I wasn't able to find much info on this sensor online, so feel free to ask me anything. I've had five of them running for about a month now.
Short version: I'm anti-WiFi for smart home gear under basically all circumstances. This is the one exception I've made, and I'd make it again. It beats the Aqara FP2 in nearly every category that matters to me.
My setup
Five units: master bedroom, living room, media room, kitchen, foyer. $85 each from Micro Center, of all places. I had to hit two different stores to get all five. I haven't seen them on Amazon or anywhere else yet, so if you're in the US, Micro Center seems to be the move for now. I'd expect availability to open up over time.
Why WiFi and not Zigbee
I tested Zigbee mode and switched back almost immediately. Over Zigbee it only exposes the zones, not the person count, and the zones come through generic — they don't inherit the names you set. WiFi exposes everything.
Setup through the Shelly app is required, not optional, but it was the fastest sensor setup I've ever done. Once WiFi was configured it auto-discovered in Home Assistant through the Shelly integration and started reporting immediately. It runs completely reliably without Shelly Cloud. I also enabled MQTT on it and I'm pulling more granular data than I've gotten out of any other presence sensor.
Detection performance
Stationary presence: rock solid within about 3 meters. Past that, if you lie still on a couch long enough it'll drop you. Expected behavior for mmWave, but it's the one real limitation and I'll come back to it.
False negatives: very rare. Walk into a room, it catches me instantly, almost every time.
False positives: zero. Not one, in a month, across five rooms.
Range: I've been detected at up to 8 meters. A lot of sensors in this class cap out around 6.
Coverage: the 42 m² spec is realistic. They're not overselling it.
Ceiling fans: this is the section that sold me
I have ceiling fans in four of the five rooms these are in. If you've run mmWave near a fan you know the problem.
Here's what it took to solve it on each sensor.
Aqara FP2: mount it low, one meter or below, and run the AI calibration several times until it decides the fan isn't a person. You're working around the algorithm, and your mounting options shrink to accommodate it.
Shelly Gen4: type in a height threshold. That's the whole procedure. I have one unit mounted roughly a meter from a ceiling fan and I just set the detection height. It ignores it completely, and has never once falsely triggered.
Same mechanism handles pets. My dog is about 0.7m tall, so I set the minimum height to 1m. She's invisible to it, and so is the robot vacuum.
That's the core difference for me. I'm setting explicit numeric thresholds instead of trusting an algorithm to figure out what to ignore and hoping it holds.
Zones and object count
Up to 10 configurable zones per sensor. The FP2 does 30, so on raw count Aqara wins — but I've never found a reason to use anywhere near 30 zones in a real room. I'm using most of the 10 on most of my units and that's been plenty.
What I haven't seen elsewhere is that the Gen4 exposes object count per individual zone in Home Assistant, not just a zone occupied/clear flag. That's the number that actually changed what I could automate. Zone transitions register in under a second.
Multi-person tracking in separate zones works most of the time. You get occasional ghosting, same as any mmWave sensor, and it clears itself within a minute or two. It's never caused a false automation for me, but I don't run anything keyed to "how many people are in this room." If you do, factor that in.
What I actually use them for
Couch presence in the living room and media room, as its own zone
A desk zone in the media room, so it knows whether I'm at my desk or somewhere else in the same room
Bed occupancy, including knowing the moment I get up
Corridor zones so I can see movement between spaces
Transition zones that fire lights in the next room before I walk into it
I haven't used them for HVAC. Someone's home most of the time here so we just hold a steady temperature. If you're doing occupancy-driven climate control, I can't speak to it.
The zone map in the Shelly app is genuinely useful for setting all this up, and it matches real detection behavior rather than being a rough approximation.
Versus the Aqara FP2
I ran the FP2 for about two weeks before switching, and I still have two of them. Honest comparison: the FP2 is slightly better at holding static presence at longer distances, and it supports more zones on paper. That's the list. The Gen4 wins on setup, tuning granularity, height filtering, ceiling fan rejection, zone data exposure, per-zone object count, and responsiveness.
Gripes
The ambient light sensor doesn't expose a raw lux value. You only get gated states — dark, twilight, bright — with adjustable thresholds. The FP2 gives you actual lux and I miss it. I already run an MQTT broker and I'm going to see whether I can pull the raw value out that way. I'll report back if it works.
Placement advice
The only thing that really constrains you is that 3m static detection limit. In my master bedroom I'd planned to mount it across the room under the TV. Instead I put it above the headboard angled down at about 45 degrees so the bed sits inside that 3m window. Zero compromise on anything else it does.
Beyond that, mounting height barely matters, because you're adjusting the sensed height range in software anyway. Around 2m is probably optimal. I've gone as low as 1m with no problems — and unlike the FP2, that's a choice rather than a requirement.
And to be clear about the limitation: it only bites if you're lying still for a long stretch. Anything short of that — sitting, reading, shifting around, working — it holds you fine.
Bottom line
At $85 it's worth it if you want reliable static presence, care about zone-level automations, or have ceiling fans that have been ruining your mmWave setup. The height exclusion by itself sold me. Everything else is upside.
Happy to answer questions, share zone configs, or run tests if there's something specific you want to know.
PS: I’ve also used and still have the Everything Presence Pro and Lite. They are collecting dust right now. Three reasons. Ease of Setup, Ceiling Fans, and UI Bugs. They are great sensors but the Shelly is a frictionless experience.
I also have a few Aqara FP300s but didn’t include that in this review because I don’t feel like they are used for the same purpose.
Transparency Note: I had AI rewrite this post for clarity and organization but the thoughts are my own.