As we know that glitch provide 4000 requests per hour for free tier
Does socket.io connection also consumes http request
if yes does that mean there will 2 requests consumed every time when user access the html file (1 for html file and 1 for socketio connection
Seems that socket.io is built on top of the websocket protocol so yes, the request to the server to establish the socket connection counts as a second request for the single page load.
Source: WebSocket requests limit