Pettersson was signed to Halmstads BK from 2016 to 2018, after playing in their U17, U18 and U19 youth leagues.

In 2018, he signed to IFK Norrköping as a free transfer until 31 December 2020.

[citation needed] In 2018, Pettersson won "Goalkeeper of the Year" at the annual Allsvenskans Stora Pris which nominates the best Swedish footballers in the country.

[1] On 5 January 2021, Pettersson signed a contract with Ligue 2 club Toulouse.

[3] Pettersson made his debut for the Sweden national team on 11 January 2019 in a friendly against Iceland, as a half-time substitute for Oscar Linnér.