A test webpage triggers a remote computer to obtain a token for the performance test from a test data collection server. The test webpage triggers the remote computer to transmit the token to a reflector server to initiate the performance test. The reflector server initiates the performance test upon validating the token. The reflector server performs bidirectional communication of test data over a Web Real-Time Communication (WebRTC) data channel using a loss tolerant protocol with the remote computer. The remote computer is able to determine computer-endpoint test results from the bidirectional communication of test data. The reflector server determines server-endpoint test results from the bidirectional communication of test data. The reflector server transmits the server-endpoint test results to the remote computer. The test webpage triggers the remote computer to transmit the computer-endpoint and the server-endpoint test results to the test data collection server.