You can include the client bundle from a CDN:


Socket.IO is also available from other CDN:

cdnjs: https://cdnjs.cloudflare.com/ajax/libs/socket.io/3.1.3/socket.io.min.js
jsDelivr: https://cdn.jsdelivr.net/npm/socket.io-client@3.1.3/dist/socket.io.min.js
unpkg: https://unpkg.com/socket.io-client@3.1.3/dist/socket.io.min.js