[3] On April 3, 2014, the singer announced on her Twitter account that "Birthday" would be released as the album's fourth single, posting its cover art as well.

[9] During a preview event for Prism, held in New York City, Perry described "Birthday" as her "attempt at writing" a song that American singer and songwriter Mariah Carey would have included in her eponymous debut album.

[10] Randall Roberts of the Los Angeles Times felt "Birthday" was a musically updated version of disco, achieved by replacing "cheesy strings" with "jerky breaks and synth washes".

[17] Jason Lipshutz of Billboard called it a "stone-cold stunner", going on to say the song "serves as pop music's (superior) answer to Swizz Beatz's "Everyday Birthday".

[10] Chris Bosman of Consequence wrote that the song was a "irrepressible disco jam" and found it superior to Carly Rae Jepsen's album Kiss (2012).

[12] Evan Sawdey of PopMatters deemed "Birthday" the "catchiest thing" on Prism, but he also thought it was a "rewrite" of Jessie J's hit "Domino" and Perry's former song "Last Friday Night (T.G.I.F.)".

[22] Lewis Corner from Digital Spy classified it as a "flirty pop-gem",[23] while HitFix's Melinda Newman awarded it a B+ grade, calling it a "delectable pop confection".

The song has sold more than 1,000,000 copies in the United States; consequently it was certified Platinum by the Recording Industry Association of America (RIAA).

This is similar to the British children’s TV series Gigglebiz consisting of the same format of cast as what Justin Fletcher did with characters in the show.

[33][34] In order to transform physically into each character, Perry spent up to seven hours getting prosthetic makeup applied by Tony Gardner.

[34] The music video begins with short introductions to Perry's alter-egos Goldie, Yosef, Kriss, Ace, and Mandee.

At another child's party, Princess Mandee paints a girl's face incompetently; Goldie begins to suffer from respiratory problems, and Yosef does the worm at a boy's Bar Mitzvah.

Goldie pulls a man's prosthetic leg off and proceeds to play air guitar with it, and Kriss crashes into a table before drinking alcohol behind a tree.

At the petting cage, Ace lets a goat run wild which defecates and urinates on the ground; meanwhile Goldie drops a birthday cake on the 90-year-old man, Yosef is then shown beatboxing at the Bar Mitzvah.

He noted that Perry had already been the center of controversy due to being dressed as a geisha for a 2013 performance of "Unconditionally", and questioned her decision to portray Yosef.

[40] Writing for Time, Nolan Feeman quipped, "Jewish people aren't costumes" and found the video distracting from the song.

[41] Ariana Bacle from Entertainment Weekly dubbed the character "anti-Semitic" and suggested that Perry should stop impersonating members of other cultures.

[42] For Consequence of Sound, Chris Coplan called the visual "incredible" and described it as a "less grating and tiresome" version of The Master of Disguise.

[43] Complex writer Zach Frydenlund positively remarked that the video "deliver[ed]" and regarded the Goldie character look as "quite nice".