Bose QuietComfort Headphones keeps disconnecting

The checks in more detail

A disconnect shows as a dropout, a stutter followed by silence, or a spoken message saying that the headphones are disconnected. Start with the basics. Check the battery: when it runs low, the headphones can drop the link before they switch off, and a long period of noise cancelling at high volume drains the battery faster than the headline figure. Charge them over USB-C. Keep the source device close, because walls, a pocket on the far side of the body and crowded 2.4 gigahertz Wi-Fi can cause stutters;

try the phone in the same room. Turn off Bluetooth on other devices that the headphones may be trying to join, since the headphones connect to the last-used device and can switch when a second one appears. The Bose app shows which devices are connected and lets you disconnect the ones you do not want. Then reset the pairing. On the phone, open Bluetooth settings, forget the headphones, and in the Bose app check for an update to the headphone firmware, which fixes known connection bugs.

Put the headphones in pairing mode, usually by holding the power key until the voice says ready to pair, and connect again. Remove old pairings from the headphones' list if the manual describes how. If the headphones disconnect only with one source, such as a laptop with an old Bluetooth adapter, the fault lies with that device; update its drivers. If they disconnect with every device after these steps, contact Bose with the serial number from the headphones.