Hi, thanks for your message!
When your attendees connect to the webinar there are a number of background messages that are sent between the browser and your server including chat messages, questions, webinar status updates, the time the attendee views the webinar etc.
Each of those messages needs a request to your server so if you have a lot of attendees that can increase the load on your hardware.
To resolve this we created WebinarPress Connect which creates a fast real-time websocket connection between our high performance servers and the attendees so when the webinar status changes or a chat message is sent all attendees are updated in real-time without having to connect to your server. That greatly reduces the load on your server. You can read more about it here.
https://docs.getwebinarpress.com/article/94-realtime-updates-using-webinarpress-servers
WebinarPress Connect has been tested with up to around 1000 attendees and is able to handle that load without any issues.
The number of attendees your server can handle without WebinarPress Connect depends on your server hardware and if you are on a hosted server or not.
If you’d like more information please send us a message at [email protected] and we’ll be happy to help.