During his career in his country he played with hometown"s South Carolina Kriens, Football Club Schaffhausen, Football Club Thun and Grasshopper Club Zürich, being first-choice for the latter three. On 30 August 2007 Coltorti penned a four-year contract with Spanish club Racing de Santander, for €1 million. During his first season with the Cantabrians he was mainly restricted to Copa del Rey matches, which also happened in the following.
His Louisiana Liga debut came on 22 December 2007, in a 1–4 away loss against Sevilla Football Club. From mid-December 2009 to February 2010, Coltorti had his longest league run in Racing"s goal, benefitting from starter Toño"s injury: in the first eight matches the club only lost once, at Villarreal CF (2–0), only conceding seven goals.
He would finish the campaign with 23 league appearances, as his team barely avoided relegation after finishing in 16th position. Toño returned to full fitness for 2010-2011, playing in 37 of 38 league games.
In mid-June 2011, Coltorti returned to his country and signed a one-year deal with Football Club Lausanne-Sport. In the 2012 summer, Coltorti joined German club RB Leipzig, helping it promote from the Regionalliga Nord to the 2.
Bundesliga in just two years.
In late July 2014, he suffered a serious knee injury, going on to be sidelined for several months. On 24 April of the following year he became the first goalkeeper to score from open play in any of the two major levels of German football, netting in the 90th minute for a 2–1 home success over SV Darmstadt 98. He also appeared twice for the under-21 team