Recently, the W3C has developed the HTML 5 standard to provide various multimedia services as well as a web based streaming. HTML5 based web browsers with the built-in video codecs can be used directly for streaming services, though previous web browsers should contain playback plug-in for streaming services. In addition, an adaptive streaming technology using HTTP/TCP has been standardized, since an Internet firewall does not support RTP/UDP streaming protocol but HTTP/TCP streaming protocol. In this paper, we propose the service migration mechanism among various devices in the HTML5-based adaptive HTTP streaming environments. The proposed algorithm and architecture were modeled for migrating media flows, media flow control, and session control and implemented using JavaScript. Finally, we showed that the proposed mechanism was effective to migrate HTTP streaming service among various devices by performing several experiments.