Critical response In 1997, "Un-Break My Heart" won a
Grammy Award for Best Female Pop Vocal Performance.
About.com reviewer Mark Edward Nero named it one of the best
R&B break-up songs and considered it Braxton's "finest moment". He further commented, "damn, this song is so sad it can make people cry for hours at a time."
Larry Flick from
Billboard magazine described it as "a
pop/R&B ballad that casts her in the role she plays best—as the forlorn heroine in a romance on the rocks." He added, "She maximizes the melodrama of
David Foster's savvy blend of stately strings and soulful rhythms, móving from a dewy-eyed whisper to a diva-like belt with theatrical ease. Hit-machine tunesmith
Diane Warren has not written a song this lyrically potent and heartfelt in a long time." Bob McCann, author of
Encyclopedia of African American actresses in film and television (2010), considered it "simply one of the most haunting R&B records ever made", while
Robert Christgau named it "miraculous" and explained "the miracle being that it's by Diane Warren and you want to hear it again." Dave Sholin from the
Gavin Report commented: "Most who hear this Diane Warren composition, which was produced with skillful guidance by David Foster, will need to take a few seconds before breathing normally again."
Insider said that the song "showcased her show-stopping voice". In a 2015 retrospective review, Pop Rescue wrote that Braxton's vocals "really shine and she's given a real range from very low to powerful highs." The reviewer added that "the music here, aside from the acoustic guitar, is absolutely secondary behind Toni's vocal prowess and the tender lyrics."
Spin journalist
Charles Aaron positively reviewed the song and joked: "this exquisitely crafted, heart-pumping l-u-v song has been droning in the produce department of my grocery store for about a year now, but I'd just like to go on record as saying that if it ever stops, I'll really be heartbroken." Richard Harrington from
The Washington Post felt it's "less sung than confessed as Braxton slips into whispered regrets and second thoughts. This beautiful song becomes a bit cinematic as it goes along and, sure enough, it turns out to be a Warren composition with a Foster production." While reviewing the album,
Stephen Thomas Erlewine of
AllMusic said the songs produced by David Foster are too predictable due to their "slick commercial appeal". However, Erlewine noted that Braxton "manages to infuse the songs with life and passion that elevates them beyond their generic confines" due to her vocal ability. Ken Tucker of
Entertainment Weekly considered the track "a tearjerker so grandiose and yet so intrinsically, assuredly hit-bound, it's the kind of mass-appeal grabber that's probably already sent a jealous
Diana Ross diving for a comfort gallon of
Häagen-Dazs." Tucker also named it the worst track on
Secrets, and further stated: "Un-Break My Heart" is "one of those the-verses-exist-only-for-the-swelling-chorus showstoppers that allude to emotions without ever actually embodying them. Braxton does her darnedest to plug some life into the song, to no avail".
Chart performance In the United States, "Un-Break My Heart" managed to peak at number one on the
Billboard Hot 100 for eleven weeks, from the week of December 7, 1996, to the week of February 15, 1997, and stayed in the same position on the
Adult Contemporary chart for fourteen weeks. The song was later ranked as the fourth-most popular song of the decade on the 1990-1999 Decade-End Hot 100 chart. In July 2008, "Un-Break My Heart" was listed as the tenth most popular song of all time by Billboard. Despite its success on the Hot 100, the song would not reach the number-one position of the
Hot R&B Singles chart, remaining at number two for four weeks behind "
I Believe I Can Fly" by
R. Kelly. It sold 2.4 million copies domestically and was
certified platinum by the
Recording Industry Association of America (RIAA). According to the
British Phonographic Industry (BPI), it has sold and streamed over 1,200,000 units there, being certified double platinum. In Australia, the song peaked at number six, and was later certified platinum by the
Australian Recording Industry Association (ARIA), for shipments of more than 70,000 units of the single. ==Music video==