Born in Kyjov (Czech Republic) 8 April 1993. Kornfeil started racing competitively in supermoto from the age of eight years, winning the 65 cc championship in 2002. Championships at national and European level in minibikes followed, as well as the Czech Republic 125GP Championship in 2007, before Kornfeil moved into the Red Bull Rookies Cup in 2008. Kornfeil finished ninth overall. His second season in the championship was more successful, with three wins in the final four races enabling him to win.After securing the Red Bull Rookies Cup, Kornfeil stepped up to Grand Prix level, making five appearances in the class towards the end of the season.In the 2010 season Jakub amassed 28 points finishes to end up 17th in the final championship standings. His best result in the season was a fifth place.Moto3 World Championship (2012–2015)In 2015, Kornfeil achieved his best result with a second place finish in wet conditions at Silverstone. He added another podium finish at Valencia, as he finished twelfth in the final championship standings.