You can check which codec is being used by the smartphone using the Sony | Headphones Connect app.
On the Headphones Connect Dashboard, check the display of codec below the model name.
This image shows an example of the Headphones Connect Dashboard screen using the WF-1000XM3 with AAC codec selected:
- The following codecs can be supported for music playback via an A2DP connection: SBC, AAC, aptX, aptX HD and LDAC, etc. For details on which codecs are supported, refer to the Help Guide for your model headphones.
- The codec being used to make a Bluetooth connection differs depending on the type of device connected, the device Operating System, software version, and device settings.