Maztr's free online Headphone Tester allows you to test your headphone or speakers using your choice of music or electronic tones.
To get started, select your sound settings then click one of the "Test" buttons. You can test Left and Right Channels separately or together. If you're testing with music, you can use the slider to adjust the spatial stereo output left and right. If you're testing with electronic tones, the slider will adjust the frequency of the tone up to 20,000 Hz. You can also select the waveform for your tone.
When using the Headphone Tester, please be careful not to let the volume get too high, particularly with the electronic tones. At high volumes and frequency ranges, it can create disturbing and potentially harmful sounds. We recommend you start low and only increase to comfortable levels.