"Stone Cold" was originally composed in the key of F minor with a "moderately fast" tempo of approximately 144 BPM.
A ballad, "Stone Cold" discusses the pain of watching an ex move on and be happy with someone else.
The song incorporates pop and soul influences, and is centered on a piano melody, with a stripped down production aimed at highlighting Lovato's vocals.
Some critics compared "Stone Cold" to Lovato's 2011 single "Skyscraper" and the work of English singer Adele.
During an interview with Ryan Seacrest, Lovato stated, "This song is your heartbreak song. I wanted to have a song that people can listen to when they're going through it, or they're thinking about a time they were heartbroken."