"If" was acclaimed for its innovation and sonic progression, as well as its sexuality and usage of multiple genres. Patrick Corcoran from Albumism called it "a pounding, fuzzed-up, nasty-sounding track that drips with the thrill of lust at first sight." David Nathan of B&S Magazine remarked that the song pulls no punches. "Listening to it and reading the lyrics Janet wrote in a Virgin Records conference room, I blush - in itself a rare occurrence." BBC Radio 3's commended it as an "impressive industrial fury" based on "oral satisfaction". Andrew Hammp from Billboard declared it a "rockin' dance track," with strings that "anchor the climax." The song's theme of avoiding temptation to interfere with monogamy was also noted, adding "Though Jackson lets her mind race with naughty thoughts [...], she ultimately stops herself from going after someone else's man." Another editor, Larry Flick described it as a "moist, seductive teaser, wrapped in an equally sexy pop/hiphop groove." He added, "Her honey-sweet voice bounces off cyborg guitar riffing, taking the rhythm-rock vibe of her Rhythm Nation hit "Black Cat" to a more intense level. Tucked beneath the pleasingly crowded production is an infectious chorus and a nifty funk bassline." Greg Kot from Chicago Tribune wrote, "There's a surprising, fuzzed-up guitar riff lifted from Peter Gabriel's 'Sledgehammer' that gives 'If' some punch." David Browne from Entertainment Weekly exclaimed it "takes Jackson into exciting new terrain," blending her vocals with "a traffic jam in a city of cyborgs." A writer for Idolator called it an "industrial dance/sex epic" in addition to "infectious and raunchy," saying "Janet Jackson's unmistakable voice is used to perfection to create an eerily tropical but beautiful track." "If" was also interpreted as "a swirling epic number", fusing "90s disco with guitar-rock," using a "Hendrix-lite guitar" throughout the song. Jackson's vocals were delivered at "break-neck speed, practically rapping about the salacious pleasures of her lover," while its production had "a lot of styles on display," including "distorted synth meets acoustic guitar."
