Far-right leader Marine Le Pen has fallen behind centrist Emmanuel Macron in the opinion polls but millions of voters are still undecided.
The two candidates confronted each other on the cost of living, Russia, climate change and immigration.
During the debate Mr Macron went on the offensive, appearing like a challenger and repeatedly interrupting his rival.
Ms Le Pen said 70% of the French people believed their standard of living had fallen over the past five years and she would be the president of civil peace and national brotherhood. "We need to give priority to the French in their own country," she said.
Mr Macron said that due to Covid, followed by war in Europe, France has known an unprecedented crisis and that he has managed through all these challenges and has made France a stronger country.
Speakdating c’est dores-et-déjà plus de 1 000 activités et leçons,
plus de 40 000 exercices, là tout prêts, dans votre poche.