from mitmproxy import http POLYFILL = """""" def response(flow: http.HTTPFlow): if not flow.request.host.endswith("flightradar24.com"): return ct = flow.response.headers.get("content-type", "") if "text/html" in ct and "" in flow.response.text: flow.response.text = flow.response.text.replace("", "" + POLYFILL, 1)