Breathe Better. Live Smarter.®

Indoor air finally becomes actionable.

Compare indoor readings with outdoor air and room history. Review possible explanations, decide what to check, and follow how the readings change.

Explore an example Explore the analytics
Status Moderate
Current driver CO₂
Data Example
Scenario Office
IAQ
42
COâ‚‚ ppm
612
PM2.5 µg/m³
7.4
VOC index
96
Page sections

Actionable Intelligence

The point is not more data. The point is better decisions.

Compare sensor readings with outdoor conditions and room history to investigate familiar events, from cooking particles to overnight COâ‚‚ buildup. Recommendations should explain what changed and what remains uncertain.

Indoor sensor
On your device
1,280 ppm COâ‚‚

COâ‚‚, PM2.5, PM10, VOC, NOâ‚“, temperature, humidity, pressure, and light.

Outdoor context
In the cloud
38 AQI

Weather, AQI, pollen, smoke, location, climate, and public data feeds.

Room history
In the cloud
5 nights/wk

Baselines, recurring events, recovery curves, seasonal shifts, and comparisons.

Suggestion
In the cloud
1 idea

Pattern detection, plain-language interpretation, and careful suggestions to consider.

Scenario synthesis

Office COâ‚‚ buildup

Today View

Your rooms and the conditions around them.

See how the room is doing, what is happening outside, and what to do next.

  • A local map puts outdoor conditions beside your room readings.
  • Easy overview status for the room and device.
  • All twelve signals for each room, plus current weather and a multi-day forecast.
  • Explore readings, trends, and the evidence behind a recommendation.
See the full analytics

Outdoor context is fused from named, authoritative sources: Open-Meteo weather and air quality, Google Air Quality (US EPA AQI), Google Pollen, and NOAA HMS / NASA FIRMS smoke.

Outdoor context · live Columbus Fog · outdoor AQI 62 · pollen —
Outdoor AQI 62 Open-Meteo · 12 min ago
Weather 41°F
Indoor IAQ 42
Wind 3 mph
Now+6h+12h+18h+24h

Indoor readings are compared with weather, outdoor air, pollen, and smoke to help you investigate possible indoor and outdoor sources.

IAQ
42
COâ‚‚ ppm
612
PM2.5 µg/m³
7.4
VOC index
96
NOâ‚“ index
1
Temp °F
71
RH %
44
Outlook day
5

Mobile App

The same intelligence, designed for your pocket.

Check each room, compare indoor and outdoor conditions, and see a clear next step when something changes.

Use the app for quick daily checks and the web dashboard when you want a longer view.

Download on the App Store Download for Android
  1. Terrestream app Today preview with example data recommending 11 minutes of ventilation and showing Indoor Air Index 15 Your air, at a glance
  2. Terrestream app Air preview with example data showing US AQI 72, source age, outdoor assessment, and a nearby-conditions map The outside world, factored in
  3. Terrestream app Rooms preview with example data comparing five sensors and room-level air signals Every room — and what to do

Terrestream for Apple Watch

Your home’s air. A glance away.

Check how a room is doing, explore its readings, and see when to let fresh air in.

Terrestream brings the essentials to Apple Watch.

Alex checking room air readings on her Apple Watch, viewed over her shoulder
Terrestream on Apple Watch: Living room, Air is good, COâ‚‚ 440 ppm

Check your rooms.

See how each room is doing.

Terrestream on Apple Watch showing COâ‚‚ and fine-particle readings

Explore your readings.

See the details behind your room’s status.

Terrestream on Apple Watch showing ventilation guidance

Know when to air.

Check ventilation guidance from your wrist.

Requires a compatible Apple Watch and paired iPhone, sold separately. Not compatible with non-Apple watches. The Watch displays Terrestream sensor data; it does not measure air quality. Screens show example data.

Dashboard View

Sophisticated analytics without the spreadsheet feeling.

Compare room trends, spot recurring changes, and examine the readings behind a recommendation. These captures of the live web dashboard use example data.

Product preview · Example data

Web dashboard overview with example data: COâ‚‚, temperature and humidity for five rooms with their last 24 hours, the outdoor outlook, and two recent episodes.
The overview: each room's latest readings beside the outdoor outlook and recent episodes.
Living room detail with example data: COâ‚‚ over the last 24 hours, rising to 846 ppm.
Open a room to follow its readings over 24 hours, 7 days or 30 days.
All twelve signals for the living room, with example data: COâ‚‚, PM2.5, temperature, humidity, VOC Index, NOx Index, IAQ, PM1, PM4, PM10, pressure and light.
All twelve signals for the room, including the calculated IAQ index.
live signals 12

Live readings

Right-now status for each room, all twelve signals, and current weather.

rolling traces 30 day

Time series

Cooking spikes, overnight COâ‚‚ buildup, recovery after ventilation, and repeating schedules.

forecast layer 5 day

Maps and outlooks

Local weather, outdoor air, pollen, smoke, and environmental outlooks.

view examples Explore

Advanced charts

Calendars, room comparisons, recurring patterns, and event timelines.

plain language Why

Interpretations

Readable summaries that explain what changed, likely causes, and what to watch next.

not noise signal

Notifications

Useful alerts when the data suggests a room deserves attention.

Rooms view

Every room on one timeline

Seven days of COâ‚‚ for five rooms on one chart, with example data: overnight rises in the bedroom, workday levels in the office and cooking peaks in the kitchen.
Outlook with example data: recorded and forecast outdoor temperature around now, current conditions (64°F, partly cloudy, US AQI 36, low pollen) and the week ahead.
Outlook: the hours around now, current outdoor conditions and the week ahead.
Calendar of the basement's daily average humidity over 30 days, with example data: most days below the 60% watch level, four days at or above it.
A calendar compares a room's daily averages with the watch level.
Home journal with example data: recent episodes by room, one still open and three with stable recovery observed.
The home journal lists detected episodes and the recovery observed afterward.
Bedroom overnight view with example data: COâ‚‚ rising from about 500 to nearly 1,000 ppm between 10 p.m. and 7 a.m., an 833 ppm average.
Overnight shows what the bedroom recorded while you rested.

Integrations

Connect your room to your routines.

Use the Terrestream skill for Alexa, or keep local workflows on your own network with Home Assistant and MQTT.

Local

Home Assistant sees every signal.

Auto-discovered entities for COâ‚‚, PM, VOC, NOâ‚“, comfort, pressure, and light without waiting on cloud automation.

  • Auto-discovery
  • 12 signals
  • Local
Home Assistant MQTT setup
Open

MQTT and local HTTP for your stack.

Publish readings to your own broker, Node-RED flow, OpenHAB dashboard, database, or monitoring pipeline.

  • MQTT
  • HTTP
  • Your broker
MQTT getting started
Alexa

Compatible with Alexa.

Link your Terrestream account to ask for supported readings and create routines. Available in the United States with Alexa set to English (US). No Terrestream subscription required.

  • Voice readings
  • Routines
  • Included
Connect Terrestream to Alexa

Breathe Better. Live Smarter.

Turn every reading into a next step.

One device. Six sensors. Twelve signals. Indoor readings connected to outdoor context and plain-English recommendations. Use Terrestream Intelligence to understand what changed, why it matters, and what to do next.

$249 USD one-time

Buy Terrestream
  • No subscription required
  • 30-day returns
  • 1-year limited warranty
  • Fast shipping via FedEx

Six sensors. Twelve signals.

Built on genuine Sensirion, Bosch, and Texas Instruments sensors.

  • COâ‚‚
  • IAQ
  • VOC
  • NOâ‚“
  • PM1.0
  • PM2.5
  • PM4.0
  • PM10
  • Temperature
  • Humidity
  • Pressure
  • Light

Included

  • In the box: the sensor, a 6 ft (1.8 m) USB-C cable, a power adapter and a printed guide
  • Free apps, web dashboard and account
  • Privacy-first air data

Compatible with Home Assistant via MQTT

WhatsApp support