Neil O'Sullivan of Financial Times called "A Change of Heart" excellent, while Maledine Roth of MTV News said the song is a "soul-wrenching (but admittedly beautiful) heap of sadness". Michael Hann of The Guardian called the track bleak and beautiful, deeming the line "You said I’m full of diseases, your eyes were full of regret / And then you took a picture of your salad and you put it on the internet" as 2016's best couplet. Celia Cummiskey of Euphoria Magazine highlighted Healy's delicate vocals and ability to mask a complicated emotional dilemma within the song's "deceptively upbeat" sound, while comparing "A Change of Heart" to Peter Gabriel's work in the 1980s. Annie Zaleski of The A.V. Club said Healy "upends the sensitive-poet stereotype with a knowing wink" and Rhian Daly of NME called the song the most self-referential track on the album. In the 1975's native United Kingdom, "A Change of Heart" peaked at number 127 on the UK Singles Chart and was later certified silver by the British Phonographic Industry (BPI), denoting sales of over 200,000 units in the UK. In the United States, the song peaked at number 47 on the US Billboard Hot Rock & Alternative Songs.
