Containing a lyrical interpolation from the song "What You Won't Do for Love" by Bobby Caldwell, the "soulful" ballad opens with a guitar-piano interplay, with Aaliyah's spoken voice noting her daily diary entry.

[1] Tonya Pendleton from The Washington Post, said it was a "seductive entreaty to an older lover to forget their age difference and allow their relationship to ripen".

[2] The song opens with "Aaliyah's spoken voice noting her daily diary entry" and it is "coupled with a delicate guitar-piano interplay that echoes the urgency of her performance".

[5] In his biography Aaliyah (2021), author Tim Footman felt the song "adds more fuel to the controversy, but the story it tells is ambiguous".

[6] He thought that a young girl taking on the role of a "sexually experienced seductress" was a little disturbing and felt that the lyrics by R. Kelly "would have fitted his own erotic persona nicely".

[7] When discussing the lyrical content of the song, Kenneth Pathridge from Billboard said, "She sings it not like a love-struck teenager but rather a poised young woman mature enough to handle a relationship with an older man".

[3] James Masterton wrote in his weekly UK chart commentary, "The new single moves back into swingbeat territory with the production trademarks of alleged lover R Kelly etched all over it.

[19] The accompanying music video for "Age Ain't Nothing but a Number" was directed by Millicent Shelton and filmed in Detroit, Michigan in late 1994.

[25] Steffanee Wang from Nylon stated "despite its unsettling backstory and origin, this song and its music video remains iconic, with Aaliyah commanding a squadron of friends at a parking lot kickback that looks something straight out of a West Side Story recreation.

[27] She also said, that her earlier videos, including "Age Ain't Nothing but a Number, "all have in common the usage of an "vignette effect, where Aaliyah is almost haloed, as the color schemes change from warm earth tone tints to black and white".

[27] In the book Diva : feminism and fierceness from pop to hip-hop (2023), the authors thought "the generic video is moody and meaningless, but splits the object of affection across a number of affable-looking male suiters".

[29] While commenting on the performance, Dejen Isaac from Uproxx said: "They changed the most blatant portion a bit (tonight we’re gonna, go "around" the way), but Nickelodeon pretty much aired a song about a teen who wants to bang an older gentleman.

[33] According to Maeve McDermott and Patrick Ryan from USA Today, "No disrespect to the late Princess of R&B, whose hypnotic vocals and idiosyncratic style remain timeless.

But it's hard not to feel at least mildly uncomfortable listening to this song in retrospect: At the time she recorded it, a then-14-year-old Aaliyah was dating — and would soon illegally marry — her mentor/producer R. Kelly, who was 27.