He was the 2020 Swedish Indoor Athletics Championships winner in the 400 metres.

After achieving the fastest mark at the trials,[5] Johannson earned his first international medals at the 2019 European Youth Olympic Festival.

[6][7] In 2020, Johansson achieved his first national title by winning the 2020 Swedish Indoor Athletics Championships.

[3] In 2023, Johansson was a member of the Swedish record-breaking team in the mixed 4 × 400 metres relay.

[3] Johannson is from Bollstanäs, Upplands Väsby and he competes for the Turebergs FK athletics club.