Home Assistant creator Simon of Byte of Geek has reviewed two Sonoff power monitors that both use Matter over 2.4 GHz Wi-Fi. The video is embedded in this post, and the full thing is worth watching: SONOFF Power Monitoring in Home Assistant – MINI PM & S60. Sonoff supplied the units, and Simon says the company had no editorial input.
What was tested
The MINI PM is built only to measure. It has no relay, so it cannot switch anything. It measures 32 by 29 by 15.9 mm, handles loads up to 16 amps and needs a neutral connection. It is meant to sit behind a light switch or socket, so a permanently wired load can be monitored while the wall switch keeps working as before.
The S60 is an ordinary smart plug with a relay. The version shown is the UK type G, rated 13 amps or 3,250 W. Simon notes Sonoff also makes Matter monitoring plugs for European and North American sockets.
How they behaved in Home Assistant
Both were added as Matter devices through the Home Assistant companion app and connected first time, according to the review. Each exposes energy, exported energy and power, with voltage and current as diagnostic entities. The S60 adds an on/off control and a power-on behaviour setting (on, off, toggle or restore previous state).
Simon’s test load on the MINI PM, a light, read just over 11 W when on and zero when off. His S60 test was a USB battery charger drawing just under 8 W. He built simple automations on both: a notification when the light stays on too long, and one when the charger’s draw falls below a threshold. He points out that a low draw does not prove the battery is full.
The MINI PM also has a local web portal Sonoff calls Open Edge. It shows power, voltage, current and frequency, with history by day, week, month or year and a data download. It also offers thresholds for current, power and voltage, plus Matter, MQTT and WebSocket settings. The thresholds cannot cut power, since there is no relay. The S60 has no such portal. Simon found a firmware update for the MINI PM that mentions better Wi-Fi reliability. Prices are around 14 to 15 pounds each.
His verdict: the MINI PM is “a great option if you simply want to monitor the power consumption of something without needing to control it.” For a plugged-in appliance you also want to switch, the S60 is the more practical pick.
What to check before buying
- Your region. The S60 shown is UK-only. In Canada, look for the North American variant, and confirm on Sonoff’s own listing that the MINI PM suits your wiring and local approvals. The video does not settle that.
- Installation. The MINI PM goes inside mains wiring. Simon says he is not a qualified electrician and recommends one for anyone not confident. We agree. Follow Sonoff’s own wiring instructions, not a video.
- Your network. These are Wi-Fi Matter devices. Home Assistant’s docs say IPv6 and mDNS must work, multicast must pass freely, and Wi-Fi Matter devices should share a VLAN with Home Assistant. Multicast filtering and misbehaving IGMP snooping can break discovery.
- Matter version. Energy readings are a basic feature, but always check that your Matter Server is current.
What owners are asking
Can I see cost per device in the energy dashboard? The video says both devices report energy and can feed the energy dashboard, but it does not show per-device cost. We have no confirmed answer, so test with one unit first.
Can Matter devices be reflashed with open firmware? Owners are debating this, and it is not settled in the material we have. Some Sonoff Wi-Fi devices run ESP32 chips, but whether these two can be flashed, or have secure boot enabled, is unconfirmed. If open firmware matters to you, buy a model that is known to be flashable instead of assuming.
Is Matter better than Zigbee for this? Our view: Zigbee is the more mature option in Home Assistant, with a bigger proven catalogue, fully local control and very low power. Matter is the industry’s direction and its strength is working across ecosystems, but it is younger. If your Zigbee plugs already monitor power, keep them until they die. For a new Wi-Fi device where sharing with Apple or Google matters, Matter is a sensible choice.