On the device you want to use with your headphones, turn on Bluetooth and choose an option to add a new device. Press and hold the pairing button on your headphones until the light on the headphones flashes. The first device should display an icon for the headphones on your screen. Select the headphones and choose "Pair" or a similar option. Type "0000" if the device prompts you for a pairing code.
While the process to connect Bluetooth headphones is the same for most devices, the exact steps to follow vary based on the brand and model headset and the other Bluetooth device's operating system and version. The first time you use a headset with another Bluetooth-enabled device, such as a cell phone, you must pair the two devices. On your phone, turn Bluetooth on and then run a scan to check for other nearby Bluetooth devices. Then, place your headphones in pairing mode. You might need to refer to the instructions for your headphones to identify the correct button to press. However, you can place many headphones in pairing mode by pressing and holding the power button until the light blinks rapidly or blinks red and blue.
Once the headset is in pairing mode, it should appear in the list of nearby devices on your phone. Select the headphones to initiate pairing. Some devices prompt you for a security code to complete the pairing process. While the exact code can vary by headphone manufacturer and model, most headphones use "0000" as the security code. Type "0000" on your phone or other device to complete the process and use your headphones.