French voters are heading to the polls to decide whether to give centrist Emmanuel Macron five more years as president or replace him with far-right candidate Marine Le Pen.
After a divisive election campaign, Ms Le Pen faces an uphill battle with her 44 year old opponent polling ahead.
In order to win they both need to attract voters who backed other candidates in the first round.
But these are two polarising figures in France and abstention is a key factor
Mr Macron's detractors call him arrogant and a president of the rich, while the far-right leader has been accused of having ties to Russian President Vladimir Putin.
Some 48.7 million people are eligible to take part and by midday (10:00GMT) turnout was down on five years ago at 26.4%, but not as low as in the first round two weeks ago. First projections of who has won will come at 20:00.
Marine Le Pen was first of the two candidates vote, which she did in her stronghold in Hénin-Beaumont. As she arrived, she sheltered a baby boy from the sun and gold him; "I will protect you".