Facebook has unveiled a Shazam-esque TV and music identification service which will allow you to tag what you are listening to or watching in your news feed post.

Friends can then preview the songs for 30 seconds or be linked to the TV show's Facebook page.

The social networking giant built the feature from scratch over the last year, and will rollout over the coming weeks for iOS and Android users. The service can bring up shows from 160 TV stations, and from millions of artists.

Facebook says the new feature is an extension of the "feelings and activity sharing" option unveiled last year. Over 5 billion posts have been shared with feelings or activity since last year, adds the company.

The new service will require users to opt-in, and if you do not, nothing will change with your Facebook experience.