In June 2002, No Angels released their second album, Now... Us!, which received critical acclaim from many critics who believed the band would not last past their first album. Another major commercial success for the group, it debuted at number one on the German Album Chart. Following an exclusive swing concert at the Berlin Tränenpalast in October, No Angels soon followed with a swing album, titled When the Angels Swing, featuring their biggest hits and selected songs from their first two albums, re-arranged by Grammy Award-nominated jazz musician Till Brönner. Critically acclaimed by critics, the album reached number nine of the German Albums Chart, eventually going gold. In November, the girls embarked on their second national concert tour, the Four Seasons Tour, playing sell-out shows in theatres across German-speaking Europe.
After Jessica Wahls' pregnancy break from the group and the end of the tour, the remaining four members of the No Angels began intensifying work on their then-untitled third studio album. Encouraged to exercise more self-control on the longplayer, the band took over responsibility in composing, recording and selecting songs to guarantee a more personal theme on the album — a step that challenged criticism and growing scepticism among the band's label Cheyenne Records and recording company Polydor.
Intermitted by a pause due to Nadja Benaissa's kneeoperation and a following physical therapy, almost all tracks except parts of the solo songs were entirely recorded at the Department-2-Studios in Frankfurt am Main, Germany. Although the album saw the quartet mainly reuniting with longtime contributors such as Thorsten Brötzmann and Peter Ries, a wider team of foreign producers was consulting. William Orbit also was in negotiations with the label, but plans fell through. "We selected song for us, which are best pop music, sort absolutely well with us, and represent at best what we want to talk about," band member Sandy Mölling said in an interview during the album's release. Impressed by the intensity of the musical output, the group settled on the album title Pure. "The music is very, very pure, [...] there's nothing we had to dissemble for, the album shows who we really are [musically]."
Although receiving a generally mixed reception from critics, Pure became the group's most critically acclaimed album then, drawing comparisons to Madonna's 1998 studio album Ray of Light as well as other female groups such as All Saints and the Sugababes. Especially praised for the implementation of the album's ballads, some critics however, criticized the band's third studio album for its "overbalancing status of filling material" and stereotypical boy band/girl group output.
Finally released on August 25, 2003 after several delays, Pure debuted at number-one of the German Media Control albums chart, becoming the band's third consecutive regular studio album to reach the top position on particular chart; number 2 in Austria and number 9 in Switzerland. Although receiving a gold certification by the BVMI for more than 100,000 sold copies, the album was a moderate success in comparison with its predecessors Elle'ments (2001) and Now... Us! (2002), eventually ranking fifty-second on the German albums year-end charts only.
The album produced three singles: Jiant-penned lead single "No Angel (It's All in Your Mind)" became the band's fourth number-one hit on the German Singles Chart, and seventh Top 10 entry in Austria. Follow-up "Someday" reached the top of the German Airplay Chart. Plans for a fourth single, a cover titled "Elevent out of Ten," originally by Swedish girl group Play never materialized when the band decided to prepare their official disbandment towards the end of the year and instead went on with the compilation album, The Best of No Angels.