The uptempo dance-pop song was written by songwriter Lee Seu-ran of Jam Factory, JQ and Choi Ji-hye, while production was handled by Becky Jerams, Pontus Persson and Kanata Okajima.
Upon its release, "You Better Know" received positive reviews from music critics due to its "anthemic" chorus and the group's EDM venture.
[2][3] Featuring energetic synths and "soaring electrified hook", the song's uplifting lyrics, which were written by Lee Seu-ran of Jam Factory, JQ and Choi Ji-hye, encourage listeners to "get ready" and "not letting go of the moment being".
While Lee Gi-seon of IZM magazine chose the track as one of the EP's highlights, Chase McMullen of The 405 website said that the song "slows things down only to build to anthemic chorus".
[10][11] In addition, it debuted at number twenty-one on the re-established Billboard K-Pop Hot 100 for the week of July 17, 2017, the highest peak position for an album track of the group.