Open received mixed reviews from music critics upon release. Peter Robinson of The Observer believed the album had "a charm and warmth which always leads back to Lewis and her charismatic vocal style."[5]Evening Standard critic John Aizlewood wrote that it was "hardly the work of a major talent", but "a pleasant, perfectly serviceable pop album".[2] Andy Gill of The Independent called the album "a considered and assured work, even if there's not, ultimately, much greater depth to it."[4]The Guardian's Alexis Petridis commented that "the second Open ends, most of it immediately vanishes from the memory, leaving virtually no trace."[3] John Mulvey of Dotmusic described Open as "frustratingly ordinary" and "like a Beverley Knight album for aspiring Notting Hill residents".[1]