Live Chat Overlay is a Chrome extension developed by Aaron Parecki. This free program allows users to restyle the YouTube popout chat and overlay it for livestreams. By installing this extension, users can take advantage of the "pop out chat" feature on a YouTube live video.

With Live Chat Overlay, users have the option to fullscreen the popout chat window and bring it into video streaming systems such as the ATEM Mini. This allows for the chat to be overlaid on the livestream using a Luma or Chroma key. Alternatively, users can obtain a remote URL to bring the chat into software like OBS, YoloBox, or Lightstream Studio as a browser source.

The key features of Live Chat Overlay include the ability to add the overlay window as a browser source to OBS or other software, change the size of the displayed comments to accommodate more text, and customize the background color of the author name and icon. Users can also choose between displaying the commenter's full name or only their first name.

Additionally, Live Chat Overlay allows users to configure a list of highlight words and auto-hide messages after a specified length of time.

Overall, Live Chat Overlay provides a convenient solution for livestreamers who want to restyle and overlay the YouTube popout chat for an enhanced viewing experience.