Jansson was born and raised in Örebro where he played for lower division locals Karlslunds IF HFK before joining Tottenham on 2 January 2007. He was spotted when playing Under-16 European qualifiers for Sweden.
At the beginning of September 2009, he joined Exeter City on a one-month loan deal.[1] He then went on to make his debut away at Gillingham where Exeter lost 3–0.[2] Exeter extended Jansson's loan till the end of October.[3]
Exeter again extended Jansson's loan deal into a third and final month until 1 December 2009.[4] He returned to Tottenham Hotspur on 1 December after completing his three-month loan deal with Exeter City. In August 2010 Jansson joined Northampton Town on a short-term loan,[5] returning to Tottenham on 7 September 2010.
On 8 August 2011, Jansson signed a one-month loan deal with Bradford City.[6] After making one League appearance and two Cup appearances for Bradford, Jansson returned to Spurs on 7 September 2011.[7]
Jansson guested for Shamrock Rovers in a friendly at Glentoran in February 2012,[8] and signed until June 2012. After being released from Tottenham, Jansson signed a permanent contract for Rovers until the end of the season.[9]
On 26 December, it was confirmed that Jansson has signed a three-year contract with Örebro SK.[10]
In the summer of 2020 Jansson announced he would leave Örebro for a bigger challenge, and in January 2021 he signed a three-year contract with Swedish top-flight club IFK Norrköping.[11]
