Breaking the Limits: Hybrid WebRTC Load Testing with k6 and xk6-browser

The WebRTC Testing Gap: Why HTTP Tools Fail In the world of standard REST APIs, load testing is a solved problem. You spin up JMeter, Locust, or standard k6, blast an endpoint with 10,000 requests per second, and measure the Time to First Byte (TTFB). If the server returns a 200 OK within 50ms, you are green. In WebRTC, a 200 OK from the signaling server is barely the starting line. WebRTC is not a request-response protocol; it is a complex, stateful negotiation followed by a continuous, high-bandwidth UDP stream. A "successful" test in the world of WebRTC requires validating a formidable chain of events: Signaling: WebSocket connection, session creation, SDP offer/answer exchange. ICE Gathering: STUN packet exchange, candidate discovery, and pair selection. DTLS Handshake: Secure key exchange for the media plane. SRTP Flow: The actual encryption and transmission of audio/video packets. Congestion Control: The bandwidth estimation (BWE) loop reacting to packet loss and jitter. Traditio