Big Machine Records released it on August 18, 2014, to promote 1989 as Swift's first pop album after her previous country image and sound.

Retrospectively, critics have considered "Shake It Off" an effective opener for 1989 as an album that transformed Swift's image from country to pop; NME and Consequence ranked it among their best songs of the 2010s decade.

In the United States, the single peaked atop the Billboard Hot 100 and received a Diamond certification from the Recording Industry Association of America.

Mark Romanek directed the music video for "Shake It Off", which portrays Swift as a clumsy person unsuccessfully attempting several dance moves.

[5] The album's diverse musical styles sparked a media debate over her status as a country artist, to which she replied in an interview with The Wall Street Journal, "I leave the genre labeling to other people.

"[20] Discussing the song's message with NPR in October 2014, Swift said that "Shake It Off" represented her more mature perspectives from her previous single "Mean" (2010), which was also inspired by her detractors.

[21] In the first verse of the song, Swift references her perceived image as a flirtatious woman with numerous romantic attachments: "I go on too many dates / But I can't make 'em stay / At least that's what people say.

[27] On August 18, 2014, during a live streaming event held on Yahoo, sponsored by ABC News, Swift announced the album 1989 and the lead single "Shake It Off" and premiered its music video.

[29] "Shake It Off" was made available for download by Big Machine on August 19,[30] and a limited CD single edition was available via Swift's website on September 11.

[35] Although positive reviews found the production catchy, critics deemed the track repetitive and lacking substance compared to Swift's works on Red.

[37] Giving the song a three-out-of-five-stars score, Jeff Terich from American Songwriter regarded Swift's new direction as "a left-turn worth following".

[18] In a positive review, Jason Lipshutz from Billboard wrote: "Swift proves why she belongs among pop's queen bees ... the song sounds like a surefire hit.

[39] In the words of Andrew Unterberger from Spin, while "Shake It Off" was musically a "red herring" that feels out of place on the album, it thematically represents Swift's new attitude on 1989, where she liberated herself from overtly romantic struggles to embrace positivity.

[41] Retrospectively, Hannah Mylrea from NME considered "Shake It Off" an effective opener for Swift's 1989 era, which transformed her image to mainstream pop.

[42] While saying that "Shake It Off" was not one of the album's better songs, Rob Sheffield from Rolling Stone applauded it for "serving as a trailer to announce her daring Eighties synth-pop makeover".

[55] The song was certified Diamond by the Recording Industry Association of America, which denotes 10 million units based on sales and streams.

[60] In the United Kingdom, it peaked at number two on the UK Singles Chart and, by November 2022, became the first song since 2020 to surpass one million in pure sales.

[20] Swift conceived the video as a humorous depiction of her trying to find her identity: "It takes a long time to figure out who you are and where you fit in in the world.

[79] Publications including the Los Angeles Times and The Sydney Morning Herald also noted references to Lady Gaga and Skrillex.

[14][24] Molly Fitzpatrick of The Guardian considered Swift "a little too skilled a dancer" for the video's concept, writing: "The incongruent blend of modern dance, ballet, and breakdancing is fun, but the conceit falls flat.

"[37] Peter Vincent from The Sydney Morning Herald called the video "unoriginal", citing the many popular culture references, and doubted Swift's success in transforming her image to pop.

[85] As observed by Wilkinson, in the video, after failing every dance routine, Swift laughs at herself implying that she will never "fit in" to "any commercially viable image, and prefers to embrace her natural zany state instead".

"[90] The Washington Post noted the video's depiction of dance moves associated with people of color, such as twerking, was another case of an ongoing debate about white pop singers embracing black culture.

[122] On October 27, 2014, the day of 1989's release, she performed the song as part of a mini-concert titled the "1989 Secret Sessions", live broadcast by Yahoo!

[141][142] One criterion for eligibility was being played on air by Triple J at least once in 2014; Swift's "Shake It Off" did not receive airplay, but a cover of the song by the folk group Milky Chance did.

[141][145] Guardian Australia's Elle Hunt wrote: "[The] virulent response to #Tay4Hottest100 has revealed the persistence of a dichotomy I'd thought we'd thrown out long ago: that of high art versus low.

"[146] On January 20, 2015, Guardian Australia submitted a freedom of information request to the ABC in regard to the station's response to the campaign and the eligibility of "Shake It Off" for the Hottest 100 contest.

[162] On January 14, 2022, Hall and Butler's legal team filed a response stating, "The rules simply do not provide defendants with vehicles for rehashing old arguments and are not intended to give an unhappy litigant one additional chance to sway the judge.

Adams said that Swift's 1989 helped him cope with emotional hardships and that he wanted to interpret the songs from his perspective "like it was Bruce Springsteen's Nebraska".

[174] The actress Reese Witherspoon and the comedian Nick Kroll performed an EDM–influenced version for the soundtrack to the musical animated film Sing (2016).