Gigwises Vicky Greer deemed Eilish to be "returning to the darker alt-pop" with "NDA", Tom Breihan of
Stereogum wrote that the song contains a "playfulness that's mostly lacking on the album" and that it is "one of the few moments where
Happier Than Ever really crackles to life".
The Forty-Fives Emma Holbrook called the song's title line as one of the darkest lyrics of the album. Writing for
Hot Press, Peter O'Neill said that certain lyrics "highlight the moody feeling of the track". Robin Murray from
Clash said that it is "delicately composed"; while Sarah El-Mahmoud of
CinemaBlend called the song "brooding" and "well orchestrated" with "intense back beat", as well as labeling the subject matter "interesting", however admitting that it did not "blow [her] mind". (pictured) in "NDA" was acclaimed by some music critics. "NDA" was praised by respective editors of
The Wall Street Journal and
Hollywood.com, with Mark Richardson commenting "[Eilish's] hushed voice and muted phrasing need the contrast these grittier and noisier tracks provide"; while Sam Persall said that it is a "perfect accompaniment to the previously released
Happier Than Ever singles" because of its diverse lyrics. Persall also described Finneas' production as "killer" and "superb", while opining that Eilish's vocal performance is "unworldly". Golsen praised the song, saying that "with a darker, almost creeper beat and near-whispered lyrics, 'NDA' shows off what Billie does best and builds up in tension and raw emotion as the song goes on". In an analysis published at
Chorus.fm, Mary Varvaris said that "NDA" has an "excellent" transition into "Therefore I Am" and that they "[complement] side-by-side and on the album". On more critical note, William said that because the song is full of details it "should make [Eilish] less relatable", however "counterintuitively, it has the opposite effect". McLevy criticized the fact that "Everybody Dies", "
Your Power", and "NDA" are placed next to each other because "following one another, they feel jarring, as though Eilish and her brother couldn't bear to leave such quality material in the studio, regardless of how inelegantly they work when placed together".
Lists Jackson Langford of
MTV Australia put "NDA" on the third place of his list compiling of every Eilish songs, where he wrote that even though the track is not relatable, it "doesn't alienate." He also compared it to previous
Happier Than Ever singles, "
My Future" (2020) and "Your Power", saying that unlike those "NDA" is an "all-out onslaught of fiery emotion as she reckons with fame's intense repercussions." Walker placed the single on the tenth position of her worst-to-best list of the artist's songs. Dailey was more critical of "NDA", hence she placed it at number 13 in her ranking of worst-to-best songs of
Happier Than Ever, explaining that the song is a "fairly unrelatable song about what it takes to have a relationship and personal life when you're an ultra-famous celebrity". ==Commercial performance==