What has changed with the Aqara FP400?
Aqara's availability announcement says the Spatial Multi-Sensor FP400 uses a 60GHz mmWave radar to track and count up to ten people simultaneously. One unit covers up to 10m x 8m (about 860 sq ft) with a 120° field of view, and you can define up to eight zones for location-specific automations. The sensor was first teased at CES 2026 and has now reached shops in the UK and across Europe and North America.
The big change from the FP2 is connectivity. The FP400 supports Thread (and so Matter) and Zigbee 3.0 instead of Wi-Fi, which means it can join an existing mesh rather than needing its own Wi-Fi link. Aqara also adds AI-assisted room mapping and says its algorithm cuts false triggers from pets, airflow and robot vacuums. It includes a built-in light sensor and can be mounted on a wall, in a corner or on the ceiling.
Aqara is selling two versions: the standard FP400 for homes, and an FP400 Pro aimed at assisted living and elder care. Gizmodo's review notes that posture detection, originally promised, has been moved to the Pro model.
| Spec | Aqara FP400 |
|---|---|
| Radar | 60GHz mmWave |
| People tracked | Up to 10 |
| Zones | Up to 8 (0.5m grid) |
| Coverage | 10m x 8m wall; 7m x 7m corner; 5m x 6m ceiling |
| Connectivity | Thread (Matter) or Zigbee 3.0 |
| Power | USB-C, 5V 1A, mains only |
| UK price | £79.99 (Aqara UK shop) |
Why does the FP400 matter for Home Assistant users?
Yes, but the feature set depends on the protocol. Aqara lists Home Assistant as a supported platform, and Thread mode needs only a Thread border router, which a Home Assistant setup with a Thread radio can provide. The catch is in Aqara's own footnote: over Thread, third-party platforms see just one overall presence sensor and one illuminance sensor.
Mighty Gadget's UK review found that you can unlock up to eight zone sensors over Matter by pre-configuring the zones in the Aqara app first. Zigbee mode through an Aqara hub gives the fullest access to zones. The same review says the headcount feature is labelled experimental, is only available in Aqara's own app, and that Aqara admits the count can be out by one to three people. Switching between Thread and Zigbee also means re-pairing the sensor from scratch.
If you run Zigbee2MQTT, note that Mighty Gadget describes support as incomplete for now. If you are new to presence sensing, our guide to presence detection in Home Assistant explains how to build reliable occupancy automations, and our Thread smart home guide covers border routers.
FP400 or FP2: which is the better buy?
The FP400 is the better choice if you want local control without Wi-Fi, but the FP2 still wins on some features. The FP400 costs about £13 more than the FP2 according to Mighty Gadget, and it doubles people tracking and widens coverage. The FP2 keeps fall detection, sleep monitoring and many more zones (30 versus eight).
Gizmodo gave the FP400 3.5 out of 5 and called it an updated but not necessarily better FP2. It reported finicky automation triggers and trouble picking up a child sitting still on the floor. Both reviews stress that the FP400 needs constant USB-C power, so there is no battery option.
UK availability and price
In the UK the FP400 costs £79.99 including VAT on the Aqara UK shop, with a free corner bracket included as a UK bonus and a two-year warranty. It is also sold through Amazon UK. The box contains the sensor, a bracket, a metal plate, a USB-C cable and a screw kit.
Should you buy the FP400 now or wait?
Buy now if you already run Zigbee or Thread and want a single sensor to cover a large open-plan room. Wait, or stay with the FP2, if you need fall or sleep monitoring, or if you want headcount in Home Assistant, which is not exposed over Matter. If you are weighing alternatives, see our best mmWave presence sensors for the UK. We have not tested the FP400 ourselves, so treat the behaviour above as reported by Aqara and the reviewers cited below.
