When your AirPod is playing in only one ear, something's wrong. The causes can range from the reasonably simple (low battery charge or dirty AirPods) to the pretty complex (problems with network or audio settings). Given that, there's no one cause for this AirPods problem, and there's no single fix, either.
If one of your AirPods isn't working, there are lots of ways to fix it. We've listed the possible fixes below, from simplest to most complex. Try them in this order to fix your AirPods.
The tips in this article for fixing when one AirPod isn’t working apply to all AirPods models, including the original AirPods, AirPods Pro, and AirPods Max.