Professional audio editing software needs a robust persistence strategy to preserve audio data captured in real time. As modern web browsers have expanded their capabilities, web applications are now able to write arbitrary data to disk in a safe and performant manner. During playback, streaming the audio from disk minimizes memory usage and start delay. In this paper, we describe an implementation of streaming audio to and from disk storage in a web application. We describe ways to address the challenges that arise from this task, such as storage quotas, cross-thread communication, and drop outs, using existing browser APIs.