SwitchBot Meter Pro CO2 Review: Accurate NDIR CO2 and a Clear Display, With a Weak Alexa Integration
A well-built CO2, temperature and humidity monitor with an accurate NDIR sensor and excellent Home Assistant support, held back by a partial Alexa integration and a slow hub.
The SwitchBot Meter Pro CO2 is a desk or wall CO2 monitor that also tracks temperature and humidity, with a large monochrome LCD you can read across the room. Its core strength is the NDIR CO2 sensor, which owners find accurate (reading the expected 400 to 450 ppm outdoors and rising quickly in a closed room), and it earns praise for its clear display, easy Bluetooth setup, rich historical data (up to two years of storage), and configurable alerts. It integrates broadly (Alexa, Google Home, HomeKit, SmartThings, Home Assistant and IFTTT, with Matter through a SwitchBot Hub), and Home Assistant users especially love it, pulling readings over Bluetooth directly. The weaknesses that pull the rating down: the Alexa integration is partial, often exposing only temperature and not CO2, so it cannot trigger automations; full remote and Matter functionality needs a SwitchBot Hub, and that hub is slow (cloud updates roughly every 10 minutes); CO2 updates only every 20 to 30 minutes on battery; and a few owners received faulty units or saw occasional CO2 spikes. For accurate, glanceable CO2 with strong Home Assistant support, it is a very good buy; for a seamless Alexa or fast-automation setup, it is less ideal.
- Home office and bedroom CO2 monitoring
- Home Assistant users
- At-a-glance CO2, temperature and humidity
- SwitchBot ecosystem owners
Pros
- Accurate NDIR CO2 sensor; reads expected outdoor levels and reacts quickly indoors
- Large, clear display shows CO2, temperature, humidity and comfort at a glance
- Easy Bluetooth setup; configurable alerts with phone notifications and a beep
- Rich historical data with up to two years of storage
- Excellent Home Assistant support (over Bluetooth or a hub); Google Home works well
- Runs on AA batteries or USB-C, with good battery life and a solid build
Cons
- Alexa integration is partial, often exposing only temperature (no CO2 triggers)
- Full remote access and Matter require a SwitchBot Hub
- SwitchBot Hub updates via cloud only ~every 10 minutes, too slow for automations
- CO2 updates only every 20 to 30 minutes on battery (30 seconds when plugged in)
- Some faulty units and occasional CO2 spikes; support can be slow
- More expensive than a simple hygrometer
Who is the Meter Pro CO2 for?
This is an indoor environmental monitor for people who want to see CO2 alongside temperature and humidity at a glance. It uses an NDIR CO2 sensor and a large monochrome LCD that shows the readings, time and comfort indicators, and it connects over Bluetooth to the SwitchBot app for alerts and history, with a SwitchBot Hub adding Wi-Fi remote access and Matter. It runs on AA batteries or USB-C power, and can sit on a desk with its kickstand or hang on a wall. It integrates with Alexa, Google Home, HomeKit, SmartThings, Home Assistant and IFTTT. It best suits home-office and bedroom users who want to know when to ventilate, Home Assistant fans, and existing SwitchBot owners. If you want a device that drives Alexa automations or reacts in real time, read the caveats first.
What buyers love
The CO2 sensor is the standout. Owners note it uses an NDIR sensor (the type found in more accurate monitors), reads the expected 400 to 450 ppm in fresh outdoor air, and rises quickly once a room is closed up, which several describe as eye-opening for home offices and bedrooms where CO2 can climb past 1000 ppm without you noticing. The large display is a favorite: clear, readable from across the room, and showing CO2, temperature, humidity, time and comfort levels without opening the app. Setup over Bluetooth takes minutes, alerts (both phone notifications and an on-device beep) are useful, and the app stores rich historical data over days, months and years, up to two years of storage. Temperature and humidity track other reference sensors well. Home Assistant users are especially happy: it can be pulled in over Bluetooth (via a proxy such as an ESP32) or a hub, updating temperature and humidity roughly every minute. It can run on AA batteries or USB-C, battery life is good, and the build feels solid.
What to know before you buy
The most common complaint is the Alexa integration: several owners report it is only partly working, exposing temperature but not CO2 or humidity, so you cannot use CO2 to trigger an Alexa automation like turning on a fan. Full remote monitoring, voice control and Matter require a SwitchBot Hub, and that hub is a weak point: it updates via the SwitchBot cloud only about every 10 minutes, which is fine for reading stats but too slow for real-time automations (one owner found it unusable for driving lights from presence sensors). On battery, the CO2 reading updates only every 20 to 30 minutes; plug in over USB-C and it can update as often as every 30 seconds. Quality control is a mild concern: a handful of buyers received faulty units (stuck at a low value, or jumping around 200 ppm when plugged in) and had to return them, and a couple saw occasional CO2 spikes to 2000 ppm and back within a minute, hinting at calibration glitches. Support can be slow, though it often follows up, and the app has had bugs (historical CO2 data disappearing, inconsistent max values).
Is the Meter Pro CO2 worth it?
If you want accurate CO2 readings on a clear, always-visible screen with strong data logging and excellent Home Assistant support, the Meter Pro CO2 is an easy recommendation, and the NDIR sensor and display are genuinely good. Set your expectations around the ecosystem: Alexa only sees a fraction of the data, real remote and Matter features need the extra-cost hub, and that hub plus battery-mode updates are too slow for fast automations. Buy it if your priority is knowing when to ventilate a home office or bedroom, and especially if you use Home Assistant, where it shines. If you need CO2 in Alexa routines, instant automation response, or a device that works fully without a hub, weigh that against what this offers first.
Frequently asked questions
Is the CO2 sensor accurate?
Generally yes. It uses an NDIR sensor, reads the expected 400 to 450 ppm in fresh outdoor air, and responds quickly to a closed room, with owners finding it credible against reference devices. A small number report faulty units or occasional spikes to 2000 ppm and back within a minute, so watch early readings and return a unit that behaves erratically.
Does it work with Alexa and Home Assistant?
Home Assistant support is excellent: it can be pulled in over Bluetooth (via a proxy like an ESP32) or through a hub, and updates frequently. Alexa is the weak spot: several owners report it only exposes temperature, not CO2 or humidity, so you cannot trigger Alexa automations from CO2. Google Home works and reports all three values.
Do I need a SwitchBot Hub?
Not for local use: over Bluetooth the display and app work on their own. But full remote monitoring, voice-assistant control and Matter require a SwitchBot Hub. Note the hub updates via the cloud only about every 10 minutes, which is fine for reading data but too slow for real-time automations.
How often does it update and how is it powered?
On AA batteries the CO2 reading updates every 20 to 30 minutes to save power; plug it in via USB-C and it can update as often as every 30 seconds. Temperature and humidity update more frequently. Battery life is good, and both the batteries and USB-C cable are included.
What does it measure and display?
CO2, temperature and humidity, shown on a large monochrome LCD alongside the time and comfort indicators, readable from across the room. It does not measure PM2.5, VOCs, radon or other pollutants, so it is a dedicated CO2, temperature and humidity monitor rather than a full air-quality analyzer.










