The Nexus 6P served as a launch device for Android 6.0 Marshmallow which introduced a refreshed interface, performance and battery life improvements, Google Now on Tap integration, a fine-grained permission model, fingerprint verification, and other new features.

[9] After the Nexus 6P was formally unveiled on 29 September 2015 at a press event at Left Space Studios in San Francisco[7] by Android Engineering VP Dave Burke,[10] It was made available with the 32 GB model starting at a price of $499.

[11] Google engineers mention that an effort was made to improve the ergonomics of one-handed use of the phone by shrinking the screen to 5.7 inches, and a singular bump on the Nexus 6 was changed to a horizontal strip in order to avoid the potential of the phone spinning when lying on a flat surface.

[11] There was push back on certain design elements, notably the centering of the reversible USB-C charging port.

This stems from a lawsuit filed by 6P owners over a bootlooping issue that caused devices to shut down randomly.

[18] The AMOLED screen used is the same generation but lower binned compared to those used in the Samsung Galaxy Note 5, the latest available as of the time of release.

[19] It was found that the phone contains a sRGB mode in "Developer Options" that increased color accuracy by lowering saturation.

Android 6.0 Marshmallow also allows website owners to set a preferred app to open their links in, and allows users greater control over this behavior.

[33] The back of the phone includes a round fingerprint recognition sensor branded Nexus Imprint below the camera.

[35] A TMD27723 digital ambient light and proximity sensor from ams AG is present on the front of the device.

This is a low-power secondary processor whose purpose is to monitor the device's movement by connecting directly to the accelerometer, gyroscope, fingerprint reader, and camera's sensors.

This chip runs advanced activity-recognition algorithms that allows it to interpret activities and gestures independently of the main processor.

The Sensor Hub recognizes when the device has been picked up and will automatically display notifications in a low-power white-on-black text until the screen has been properly activated.

The screen is protected by a panel of Gorilla Glass 4, while the back and sides are aeronautical-grade anodized aluminum.

[44] There is a rear bump that spans the width of the phone that houses the camera sensor, LED flash, laser auto focus, NFC coil, GPS, Bluetooth, Wi-Fi and cellular antennas.

[51] The Verge considers the Nexus 6P as "the best" Android phone with "beautiful hardware and a camera that can finally compete".

[52] Anandtech praised the camera as a "high-end performer", but was critical of the price outside North America and Europe.

[54] iFixit gave the Nexus 6P a 2 out of 10 in terms of repairability, praising the solid construction which improved durability, but mentions that it is "very difficult" to open the device without damaging the glass camera cover due to the unibody design, and panned the difficulty in replacing the screen and the adhesive holding the rear cover panels and battery in place.

The cause of this issue is suspected to be the lack of expansion joints, which makes the glass susceptible to thermal shock when there is a sudden temperature change, like entering a warm room from cold outside.