"Iggy SZN" received mixed reception from
music critics. An editor from the website Music Times compared the minimal production on the track to that of Azalea's previous single "
Fancy" featuring
Charli XCX (2014), writing that "It's not quite as catchy as 'Fancy,' but it is still a lot of fun." Brennan Carley of
Spin opined that the background on "Iggy SZN" was similar to works done by
Diplo. He further shared that, "she'll need to do a little better than 'Iggy SZN' if she wants to keep anyone's interest." Jim Farber of the
New York Daily News commented "the star doubles down on her love of 'fancy' (read: gimmicky) hooks, pitting a shrill beat, a lion's roar and a nagging synth against one another for attention." Mike Wass of
Idolator, while reviewing
Reclassified, said that, "Of the trio of fuck-you anthems, 'Iggy SZN' is the most light-hearted and upbeat. It showcases Iggy's knack for memorable quips – 'what they make in a year, I can make in a week' – and The Invisible Men's ability to deliver crazy beats." Rory Cashin of
State added that the song is "built on hand claps and a deep electronic buzz, which will sound great in a high tempo
Zumba class." David Jeffries of
AllMusic also complimented "Iggy SZN" stating that it "is wonderful schoolyard silliness and helps to add some charm to Iggy's ice-queen persona". The track entered and peaked on the
Australian Singles Chart at number ninety-five. It also charted at number nineteen on the
Rap Digital Songs chart and twenty-four on the
R&B/Hip-Hop Digital Songs after the song being unlocked on the
Reclassified album pre-order, resulting in a number forty-eight debut on the
Hot R&B/Hip-Hop Songs chart dated 29 November 2014. Moreover, the track debuted at number sixty-three on the
Hot Canadian Digital Songs. ==Live performances==