The recording sessions took place the day after Spears filed for divorce from Kevin Federline, and members of the Clutch claimed to be surprised by her work ethic.

The song was then planned as the fourth single, but the release was cancelled as Spears began recording her sixth studio album, Circus (2008).

"Radar" was later included on Circus, and officially released as the fourth and final single from the album on June 22, 2009, by Jive Records.

Spears' vocals are auto tuned and accompanied by sonar pulses and a heavy usage of distorted synthesizers.

After it was released as a single from Circus in 2009, the track performed poorly on the charts and did not manage to enter the top 40 in most countries.

[1] In November 2006, Spears recorded "Radar" with Ezekiel Lewis and Patrick M. Smith of the Clutch at Sony Music Studios in New York City.

Both commented that although Spears arrived late to the recording sessions, she caught them off guard with her efficiency and professionalism, with Lewis adding, "It was absolutely nuts, and she took directions very well.

[4][5] However, a wider release was scrapped when Spears began recording new material for her sixth studio album, Circus.

[15] Roger Friedman of Fox News said that along with "Break the Ice", "Radar" was more "straight-ahead electronic disco" than the rest of Blackout and added that it "sounds like Las Vegas goes Eurodisco.

"[13] Spears sings lyrics such as "Confidence is a must / cockiness is a plus / edginess is a rush / edges I like 'em rough / A man with a Midas touch / Intoxicate me I'm a lush.

"[21] Nekesa Mumbi Moody of USA Today called it "a sexy techno groove that you can't help but bounce to.

"[22] Theon Weber of The Village Voice said that "Spears's writers present her with the goofiest, most vivacious productions she's ever had, filling 'Radar' with pinging noises and polishing Madonna's dance-floor trash bright.

"[23] Nick Levine of Digital Spy called it "a rave-tinged electro blipathon on which Spears is vocodered to the point of sounding extra-terrestrial.

"[12] A reviewer from the Ottawa Citizen said that "some tracks [of the album] just don't work, such as Radar, in which Britney's voice is tuned up so high she sounds like she's 14.

"[24] Laura Herbert of BBC News said that many of the album's songs, including "Radar" and "Toy Soldier" "are repetitive and over-produced.

"[26] Chris Wasser from the Irish Independent said the album had single potential, exemplifying that "There's little doubting we'll hear the bouncing and digitally affected vocals of Radar and the livelier Hot As Ice on the radio soon enough, but both tracks still seem a little under par.

[3] The music video for "Radar" from Circus was filmed on May 27 and 28, 2009, at the Bacara Resort & Spa located in Santa Barbara, California.

It was directed by Dave Meyers, who previously worked with Spears on her music videos for "Lucky", "Boys" and "Outrageous" as well as the Curious commercials.

[10] He had a very clear idea of how he wanted the story line to work: "There is a narrative going on, a romantic triangle on a weekend at this polo mansion," he said.

Since the song was not the first single from Circus, Meyers chose to experiment and not have dancing scenes, saying that "the videos are a chance for her to vocalize a sense of herself.

[43] Daniel Kreps of Rolling Stone said the music video was her weakest since "Gimme More" and highlighted the comparisons with "Take a Bow", saying, "while Madonna dressed the role of a distressed aristocratic senorita in the stands, Spears’ wardrobe and giant hat mirror the elite at the Kentucky Derby".

He commended it for its "more straightforward approach in telling a so-called story", but felt it was "a bit too much like one of those overly dramatic fragrance commercials".

She wore a black bra encrusted with Swarovski crystals, fishnet stockings and high-heeled laced up boots, designed by Dean and Dan Caten.

Spears ended the performance with her and her dancers posing in the middle of the three-ring stage as a red curtain slowly descended in the closing.

[49] In the revamped Britney: Piece of Me concert (2016), "Radar" plays during an interlude that features multiple excerpts of Spears' music videos.

[50] The song appears on the 2023 TV series Wilderness' third episode, titled "Repent at Leisure", while the character Liv, portrayed by Jenna Coleman, runs through the forest.