[3][4] "Don't Be So Hard on Yourself" was written by Jess Glynne, Wayne Hector with its producers Tom Barnes, Peter Kelleher and Ben Kohn, also known as the production team TMS.

Rachel Sonis of Idolator named it a "massive floor-filler",[10] while Bianca Gracie of the same publication noted that "there is a refreshingly somber tone that saves it from being too predictable.

"[6] Amy Davidson of Digital Spy gave the single 4 out of 5 stars stating, "[W]ith her vocals shooting to the very perimeters of the track, 'Don't Be So Hard On Yourself' sees Glynne continue to wear her disco influences on her sleeve for a new take on the well-worn 'feel-good anthem'.

[12] While recommending the song for download, Andy Gill of The Independent wrote that "[it] could be the project's mission statement, with Glynne's darkly tremulous delivery a kind of turbo-powered warble that conveys strength overcoming tribulation, a message under-scored by the rising figure of the backing vocals.

"[14] Matthew Scott Donnelly of Pop Crush opined that the song "uses upbeat soul as a vehicle to deliver sonic-cheeriness, [...] becom[ing] a warning against self-deprecation.

"[15] Andy Baber of MusicOMH called it "irresistibly catchy", praising the fact that it "relies simply on a driving clapped beat and a jaunty piano riff.

"[17] Hazel Cills wrote for Spin noted that the album can be "relentless in this 'lift yourself up' message, citing the song as "the cream of this crop", observing that is "punctuated by swooning violins and a house-evoking piano melody fit for the club.

[19] The following week, after its release, the song reached the top of the charts, becoming her fifth number-one single, matching the record for a British female solo artist, held by Cheryl.