Why Are There Two Lists on Facebook Chat?

You can have hundreds, or even thousands, of friends on Facebook. However, chances are you don't keep in regular contact with all those friends. The people who appear in the top of the Facebook chat sidebar are the people you've recently talked to or regularly interact with. This is a convenience feature to keep the people Facebook thinks you most likely want to chat with easily accessible at a glance.

The lower part of the Facebook chat sidebar, under the label "More Friends," lists your other Facebook friends who happen to be online. While the top list will display friends whether they're online or not, the bottom list only displays friends who are currently online and available to chat.

You can't manually set which of your friends show up in the top list in your Facebook chat bar. Facebook uses data from your sessions to figure out who you've chatted with lately and who you chat with on a regular basis. It then puts those friends in your top list. Facebook will add people to this list as you talk to different friends, and remove people from the list if you don't talk with them for a while.

If you want to send a chat message to someone who isn't visible in either list you can use the search field at the bottom of the chat sidebar. Typing the friend's name into that field will make his name appear in the sidebar, so you can click the name to open a chat window with him. You can also use the search field as a shortcut to find a specific friend from the much longer bottom list.