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How fresh is the air at the places you go?

airnetters is a lookup site for indoor CO₂ readings of public places, a simple stand-in for how well a room shares fresh air.

Poor

2000+ ppm

Okay

~1200 ppm

What the colors mean

Higher CO2 usually means more shared air, including whatever else people are exhaling. These zones are a starting point, not medical advice.

Fresh

Under 800 ppm

Air is being shared well.

Okay

801–1200 ppm

Air is getting a little stale.

Stuffy

1201–2000 ppm

Not much fresh air coming in.

Poor

Over 2000 ppm

Very little fresh air. Many people may feel it.

Zones: Fresh ≤ 800 ppm · Okay 801–1,200 ppm · Stuffy 1,201–2,000 ppm · Poor > 2,000 ppm. Thresholds informed by ASHRAE's 2025 Position Document on Indoor Carbon Dioxide, Health Canada's 1,000 ppm long-term residential guideline, and the community scale popularized by Aranet meters.

Look up before you go

Each place has its own page with recent readings, conditions, and a clear color.

Share what you measure

Bring a CO2 meter, take a reading, and post it in under a minute.

Private by default

No accounts required. We never store raw IPs or precise device info.