"Beautiful Liar" was released on February 12, 2007, through Columbia Records and Music World Entertainment as the only single from the deluxe edition of the album.

The song peaked at number one in various European countries, including France, Germany, Hungary, Ireland, Italy, the Netherlands, New Zealand, Switzerland, and the United Kingdom.

"Beautiful Liar" was written by Mikkel S. Eriksen, Tor Erik Hermansen, Amanda Ghost, Ian Dench, and Beyoncé.

[2] The first three attempts were not satisfactory, and Smith put Eriksen and Hermansen to work together with Ghost and Dench, who wrote a significant part of the lyrics and the melody.

[2] She recorded a solo version a few months before the release of the deluxe edition of B'Day (2006) adding new lines and producing the song alongside Eriksen and Hermansen, handling the vocal production and arrangement.

[3] In another interview for MTV News, Beyoncé said that she met Shakira several times at various awards shows, and they talked about plans to collaborate on a song as they are both fans of each other and respect each other's work.

[1] "Beautiful Liar" is a R&B and latin pop song, which is written in the key of G Phrygian dominant, and set in common time at a tempo of 96 beats per minute.

[8] The song opens with Shakira's vocals accompanied by a piping, Middle Eastern figure, later joined by a mariachi-flavored horn section.

[8] The verses are sung on a mid-tempo, strutting, hip-thrusting arrangement, accented by rapid, flamenco-like hand claps and guitar strums.

"[4] The chorus features the lines, "Let's not kill the karma, let's not start a fight" with the female protagonists bonding in their mutual betrayal.

Beyoncé sings the lines "I didn't know about you then, till I saw you with him again" earnestly while Shakira later adds "I walked in on your love scene, slow dancing".

[23] Celis produced and mixed a Spanish-language version,[5] titled "Bello Embustero", with additional lyrical contributions by Rudy Pérez.

[1][25] Nick Levine of Digital Spy awarded "Beautiful Liar" three stars out of five and wrote that it "isn't as ridiculously overblown" as previous collaborations of Whitney Houston and Mariah Carey on "When You Believe" (1998) and Barbra Streisand and Celine Dion on "Tell Him" (1997).

[26] However, he added that "it's as calculated as a wannabe page 3 model's decision to have a boob job", and that an accompanying music video will keep fans happy.

[27] Richard Cromelin of the Los Angeles Times wrote that the singers "have fun with the grand soap-operatics" of the song adding that "Beautiful Liar" has "cultural as well as musical resonance, furthering Beyonce's bilingual agenda".

[9] Chris Willman of Entertainment Weekly wrote that the song "is a minor letdown; Shakira's voice is too like Beyoncé's for a truly complementary tango".

[29] Erika Ramirez and Jason Lipshutz of the same publication ranked the song at number 22 on their list of "Beyonce's 30 Biggest Billboard Hits".

[30] In 2014, Emily Exton of VH1 placed the track on her list of Shakira's best duets, calling it a "sexy ode to the men we know we can't trust" and praising both singers for their complementing vocal performance.

"Beautiful Liar" was certified platinum by the Recording Industry Association of America (RIAA) in February 2009, denoting shipment of one million copies.

[47] The Australian Recording Industry Association (ARIA) certified "Beautiful Liar" two times platinum, denoting shipment of 70,000 copies.

Music wrote that the dance moves of Beyoncé and Shakira in the video were convincing and erotic "without reaching the point of tackiness.

[26] James Montgomery of MTV News noted that the music video "is enough to give you whiplash" due to Beyoncé's and Shakira's dance abilities.

[56] Sal Cinquemani of Slant Magazine praised the scene during the bridge of the song, where Beyoncé and Shakira "begin mirroring each other's movements".

[64] Beyoncé was accompanied by two drummers, two keyboardists, a percussionist, a horn section, three backup vocalists called The Mamas and a lead guitarist, Bibi McGill.

"[67] Shaheem Reid of MTV News compared the performance with Michael Buffer further adding that "Beyoncé acknowledged Shakira by shaking her hips rapidly".

[65] While reviewing Beyoncé's performance of the song in Saskatoon on September 14, 2007, a writer of The StarPhoenix noted that it was one of the musical surprises during the evening.

[69] In Los Angeles, on September 2, Beyoncé performed "Beautiful Liar", dressed in a green belly-dancing outfit, with several female backup dancers, and live instrumentation.