Pixel Phone Temperature Sensor: How It Works

Yes, your Pixel phone can measure temperature, but only the surface temperature of objects, not body or ambient air temperature. The Pixel 8 Pro and Pixel 9 Pro series include a dedicated infrared (IR) temperature sensor, accessible through the built-in Thermometer app, that reads the thermal radiation emitted by a target object when you point the phone at it.

Background: How the Sensor Got There

Google introduced the temperature sensor on the Pixel 8 Pro in late 2023, and kept it on the Pixel 9 Pro and Pixel 9 Pro XL in 2024. The sensor is a small infrared thermopile located on the rear camera bar, near the flash. It was initially marketed for measuring the temperature of objects like a mug of coffee, a frying pan, or a baby bottle. The feature drew attention because it was the first mainstream smartphone in the U.S. to include such a sensor since the short-lived Cat S60 (which was aimed at industrial use).

Google initially disabled the sensor for measuring human body temperature, citing regulatory and safety concerns. In early 2024, a software update enabled body temperature measurement, but only through the Thermometer app on the Pixel 8 Pro and later models. The feature is not available on standard Pixel 8, Pixel 9, or Pixel 9 Pro Fold—only the Pro models with the sensor hardware.

How the Infrared Sensor Works

The sensor measures the infrared radiation emitted by an object. All objects above absolute zero emit infrared radiation, and the amount increases with temperature. The thermopile detects this radiation and converts it into an electrical signal, which the phone’s processor translates into a temperature reading using a calibration algorithm.

Key limitations to understand:

• It measures surface temperature, not internal temperature. For example, it reads the surface of a pot, not the soup inside.
• It cannot measure through glass, plastic, or other transparent materials—those block or reflect IR.
• It is not accurate for measuring air temperature; the sensor needs a solid target.
• For body temperature, the phone must be held close to the forehead (about 5 cm away) and the reading takes a few seconds.

How to Use the Thermometer App

To measure an object’s temperature:

1. Open the Thermometer app (pre-installed on Pixel 8 Pro and later Pro models).
2. Select Object temperature.
3. Point the sensor (the small dot on the back) at the target from a distance of about 5–10 cm.
4. Tap the round button to start measurement. The app will show a live temperature reading.

For body temperature, select Body temperature in the app, then gently place the phone’s sensor area against your forehead (the app guides you). The reading takes about 2–4 seconds. The app will ask for age and gender—these are used for the calibration algorithm, not stored.

Note: The body temperature feature is only available in certain regions and requires the phone to be updated. It is not a medical device; readings are for general wellness.

Accuracy and Common Problems

Accuracy depends on several factors:

• Distance: Too far or too close gives inaccurate readings. The app shows a distance indicator.
• Emissivity: Shiny or reflective surfaces (like polished metal) emit less IR, leading to low readings. Matte, dark surfaces work best.
• Obstructions: Dust, moisture, or a case covering the sensor will block the signal.
• Calibration: The sensor can drift over time. Google recommends occasional recalibration using a known reference (e.g., an ice bath at 0°C/32°F).

Common issue: Users report that the sensor reads too low for hot objects like a pan. This is usually due to the pan’s shiny surface. Try measuring a matte area or placing a piece of black tape on the surface.

Another issue: The app may show “Cannot measureâ€� if the target is too hot or too cold (outside the sensor’s range). The sensor works from about -20°C to 150°C (-4°F to 302°F).

Comparison with Other Temperature Sensors

Smartphones with IR thermometers are rare. The only other recent mainstream phone with a similar sensor is the FLIR One series, but that’s an external attachment, not built-in. Some older phones like the Samsung Galaxy S4 had a temperature/humidity sensor, but that measured ambient air, not surface temperature.

Compared to a dedicated infrared thermometer (like a medical forehead thermometer), the Pixel’s sensor is similar in technology but less precise for medical use. The Pixel’s body temperature feature is not FDA-cleared for medical diagnosis; it’s for general wellness tracking.

Safety and Privacy Considerations

Safety:

• Do not point the sensor at the sun or a laser beam—it could damage the sensor.
• Do not use the sensor to measure body temperature if you have a fever and are seeking medical advice; confirm with a medical-grade thermometer.
• The sensor emits no radiation; it only detects IR, so it is safe for all ages.

Privacy: The Thermometer app does not store temperature history. Body temperature readings are processed on-device and not uploaded to Google servers unless you choose to share them. The app asks for age and gender for calibration, but you can skip it.

Alternatives to the Pixel Sensor

If you don’t have a Pixel 8 Pro/9 Pro, or you need a more accurate or versatile thermometer, consider:

• Standalone IR thermometers: Inexpensive (around $15–$30) and accurate for cooking and home use.
• Medical forehead thermometers: Specifically calibrated for body temperature, with clinical validation.
• Probe thermometers: For cooking, a probe gives internal temperature, which the Pixel cannot.
• Smart home sensors: Some smart displays (like Echo Show) have temperature sensors, but they measure ambient air.

The Pixel sensor is a convenience, not a replacement for dedicated tools. For most people, it’s a fun gadget for checking a hot pan or a baby bottle, but for critical tasks like cooking meat or monitoring a fever, use a proper thermometer.

Frequently Asked Questions

Can the Pixel phone measure air temperature?

No. The IR sensor measures surface temperature of a solid object. It cannot measure air temperature because air does not emit enough IR for the sensor to detect. For ambient temperature, use a separate thermometer or a weather app.

Is the Pixel temperature sensor accurate for body temperature?

It’s reasonably accurate for general wellness, but not as precise as a medical-grade thermometer. Google states it is not intended for medical diagnosis. If you need an exact reading for a fever, use a dedicated medical thermometer.

Why does my Pixel show “Cannot measure� for a hot pan?

This usually happens if the pan is very shiny (low emissivity) or if the sensor is too far away. Try measuring a matte area, or place a piece of black electrical tape on the surface and measure that. Also, ensure the sensor is clean and unobstructed.

Can I use the Pixel sensor to measure the temperature of a baby bottle?

Yes, but only the surface temperature of the bottle. The milk inside may be different. Shake the bottle and measure the side, or use a probe thermometer for an accurate internal reading. Always test the milk on your wrist before feeding.

Does the temperature sensor work on all Pixel phones?

No. Only the Pixel 8 Pro, Pixel 9 Pro, and Pixel 9 Pro XL have the hardware. The standard Pixel 8, Pixel 9, and Pixel 9 Pro Fold do not include the IR sensor. You can check if your phone has the Thermometer app; if it’s not there, your phone doesn’t have the sensor.

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