For the album, Perry worked with numerous producers, including Jeff Bhasker, Mark Crew, Duke Dumont, Jack Garratt, Oscar Holter, Illangelo, Ilya, Max Martin, Ali Payami and Shellback.

[3] Perry decided to shed her on-stage persona and embrace her self-proclaimed authentic self as Katheryn Hudson, her real name.

[5] She decided to take a hiatus after the tour concluded to "give my mental health a break" before starting to write new songs the following June.

[6] In August, the singer stated that she aspired to make material "that connects and relates and inspires"[7] and told Ryan Seacrest that she was "not rushing" her fifth album, adding "I'm just having a lot of fun, but experimenting and trying different producers, and different collaborators, and different styles.

[10] Later that month, she told Capital FM that "I've got something swirling, but I think I want to put out some songs first before I give them the full meal.

"[11] The following May, Perry revealed to Entertainment Weekly that the album would include 15 of the 40 songs she wrote for it, and described the record as "fun and dance-y and dark and light.

Club, hooks are in short supply, replaced by grooves and atmosphere that pick and choose elements from 1990s house music, mainstream EDM, electro-tinged hip-hop, and 1980s new wave.

"[21] "Power" is an electro[22] composition, which explores a theme of self empowerment, Jillian Males from Pitchfork noted that the song "approximates feminism by politicizing a personal struggle for control.

"[24] On September 29, 2017, Urban Outfitters released a limited-edition exclusive vinyl of the album with alternate cover art.

[25] Billboard's Tatiana Cirisano listed the album cover as one of the worst of 2017, characterizing its "freaky alien theme" as "just a tad too horrifying".

[41] Hannah J. Davies of The Guardian gave the album a rating of 4 out of 5 stars, writing that the singer "still has a flair for tunes that quickly seep into the collective consciousness" and praised "Swish Swish" as "a house-fuelled banger with undeniable groove," though felt that "Perry's heartfelt ballads feel tacked on in the face of all this weirdness.

"[44] Leonie Cooper from NME gave it the same rating and complimented the same track, arguing that while the album lacked subtlety, this is justified when "[delivering] important messages about female autonomy to a young audience".

[45] USA Today's Maeve McDermott commended the album for being "sonically coherent" and noted it as a personal record, rather than the politically charged one that the marketing campaign for it had suggested.

He did not feel it had "introspection or maturity," though praised "Miss You More" as "the kind of brutally honest anthem that Katy isn't given enough credit for," and dubbed it "the album's emotional core."

Wass concluded that "Witness might be overly ambitious and is definitely a couple of songs too long, but dance-pop experiments don't come much more enjoyable than this.

[42] Giving Witness 3 out of 5 stars, Christopher R. Weingarten wrote in Rolling Stone that it was comparable to the music of Halsey and Camila Cabello, and that the songs blended "into the rest of the radio."

"[19] AllMusic's Stephen Thomas Erlewine gave the album 2 out of 5 stars, saying it felt "relentless and a shade desperate" and called the record "a conceptual muddle."

"[15] The Daily Telegraph journalist Neil McCormick gave Witness the same rating, and panned the usage of the term "purposeful pop" for the songs.

Wood was critical of the musical direction on Witness, the supposed "purposeful pop" being lost in the tracks and Perry's singing.

[51] According to Jordan Sargent from Spin, the record "feels like it's making a bid for a level of artistic seriousness—a recognition of aesthetic vision—that Perry has never really been afforded."

[56] According to Billboard, it was the country's eighth-highest performing album of the 2017 summer season, earning 431,000 album-equivalent units in the nation by September 2017.