In this paper, feasibility of web based breathing exercises for respiratory rehabilitation is examined. A system included visual guidance in a web browser and a microphone equipped headset for biofeedback and interaction. Feasibility was assessed in a controlled environment on 34 subjects with anxiety disorders that were not offered any help from the personnel. Weak points of comprehensibility were identified as applying headset (21%) and adhering to breathing exercises instructions (7%). No adverse events were identified. Design flaws that correlated with poor user’s experience were 1) the unpleasant feelings induced by watching the computer screen (21%) and 2) ease/difficulty of physically applying headset (14%). We conclude that conducting breathing exercises by using an acoustic microphone and a web browser is feasible and should be further researched. Additionally we conclude that audio feedback might be more pleasant to some people.