ChatGPT is working on a companion window feature for the web. This new option will allow users to open conversations in a draggable companion window, which is already supported on the macOS app. The companion window can hold conversations that are different from what you have on the main screen, helping to boost productivity by allowing for multiple interactions at once.
It is very likely that this feature will be integrated into the upcoming Windows app, which is rumored to be built on Electron. As for the web itself, official support for this feature may not be included immediately. However, there is a possibility that the feature could eventually be released as part of the Progressive Web Application (PWA), which would enable users to use the companion window on the web as well.