Plurk is a free social networking and micro-blogging service that allows users to send updates (otherwise known as plurks) through short messages or links, which can be up to 140 text characters in length.

Updates are then shown on the user's home page using a timeline which lists all the updates received in chronological order, and delivered to other users who have signed up to receive them. Users can respond to other users' updates from their timeline through the Plurk.com website, by instant messaging, or by text messaging.