Seeking advise on embeddable web chat clients that connect to irc networks.

Currently I am using a lightirc embedded chat box on my webpage.
When I do speed tests upon my page using gtmetrix, I often get warnings about using FLASH. or advise to delay the loading of flash or java scripts.
I've looked into other embeddable webpage chats ( to irc), like kiwiirc but always, these embeddable chat boxes cause slow speeds on my page. of course java scripts and flash applications will slow down a page.

Does anyone here know how to code in html5; a embeddable webpage portal chat client to irc without using flash?

I know that the Firefox new updated browser does not support flash. This means that every person who updates to the new firefox browser cannot open the chat box on my webpage. I also suspect that over time, flash will be phased out. Google is already down-ranking sites with flash.

Any advise would be helpful.