Miller from NME described the song as "an expertly conceived tear-jerker", stating that "[i]t feels like the kind of song a teenage Stefani, miming along to Talk Talk, would have dreamt of singing one day." Bill Lamb from About.com cited "4 in the Morning" as the best song on the album, calling it "beautifully performed and produced", and noting that Stefani "allows her signature vocals to sensually float and glide through the lyrical content." Similarly, a reviewer for CBBC enjoyed that the song is "a melancholy and reflective ballad about relationships, which is a breath of fresh air for Gwen", praising its "catchy melody and woeful lyrics." Nick Levine from Digital Spy compared it to Robert Palmer's 1986 single "Addicted to Love", writing that "it confirms what is rapidly becoming a universal truth: Gwen Stefani is far more likeable when she channels her new wave roots than when she tries to mould herself into a ghetto fabulous urban hipshaker." Sal Cinquemani from Slant Magazine praised Kanal's production for making the song "less forced and much less self-conscious." Quentin B. Huff from PopMatters referred to it as one of the "few real compositions" from the album. John Murphy from musicOMH agreed, writing that "she sounds great" on "the lovelorn ballad." Pitchforks Mark Pytlik, however, disapproved of the song, commenting that it destroyed "the mallpop cred that Stefani accrued with Love. Angel. Music. Baby.s impeccable 'Cool'." Spence D. from IGN was also critical with the song, calling it "the most generic, mainstream, and blasé-blah pop song on the entire album." Chart performance In the United States, "4 in the Morning" debuted at number 76 on the US Billboard Hot 100 for the week of June 9, 2007, before peaking at number 54 on the issue dated August 4, becoming Stefani's lowest-peaking solo single on the chart at the time, and her first to miss the top 50. It was somewhat more successful in the mainstream market, reaching number 30 on the Pop 100 chart and the top 20 of the Mainstream Top 40 and Pop 100 Airplay charts. The single was also successful at nightclubs and reached number two on the Dance Club Songs chart. In Canada, the single fared better, where it peaked at number 17 on the Canadian Hot 100, but was more successful outside of North America. In Australia, the single debuted and peaked at number nine on the