A browser-based debugger application is configured to debug a second browser based application. A channel repeater module is invoked to establish a bidirectional communication channel between the debugger application and the second application. A start indication is transmitted from the second application through the channel repeater module. The second application enters a blocked wait state. A debug operation is performed on the second application. A debug request message is transmitted to the second application through the channel repeater module to cause the second application to transition from the blocked wait state to a run state and to perform a debug action indicated by the debug request message. A response to the debug request message is received from the second application through the channel repeater module. The second application transitions to the blocked wait state from the run state.