Now it is clear, France will decide between a centrist newcomer who has served as economy minister but has never before been elected and the leader of France's far-right.
Emmanuel Macron is favourite to win the presidency on 7 May, but Marine Le Pen of the National Front has attracted a record number of voters.
Opinion polls taken since the first-round result suggest he will win at least 60% of the vote, but a significant number of voters are undecided after the first round.
The poll tracker begins with surveys taken between early January and the 23 April vote, before there were two clear candidates.
The polling average line looks at the five most recent national polls and takes the median value, ie, the value between the two figures that are higher and two figures that are lower.
Analysis of voting patterns from the 23 April first round shows Ms Le Pen gained most votes in the north-east and south-east of France, where the National Front has traditionally seen its strongest support.
Mr Macron gained most support from more westerly areas, and he also fared well in parts of Paris.
One of the overriding issues facing French voters is unemployment, which stands at almost 10%. One in four under-25s is unemployed.
Latest EU figures show France has the seventh highest unemployment rate of all member states, 2% higher than the EU average.
The French economy has made a slow recovery from the 2008 financial crisis and both candidates are calling for deep changes.
Ms Le Pen has proved popular with the unemployed as well as younger voters who are frustrated about the lack of jobs and France's poor economic prospects.
Mr Macron was economy minister in President Francois Hollande's government and is promising a series of liberal reforms including cutting public spending and business taxes.
Security and immigration are also high on the agenda.
France is still in a state of emergency after the terror attack on Nice on 14 July 2016 when a lorry ploughed into a crowd celebrating Bastille Day.
More than 230 people have died in terror attacks in France since January 2015 and the murder of a policeman on the Champs Elysées three days before the first round was a deadly reminder of the threat from militant Islamists.
Officials fear more of the hundreds of young French Muslims who have travelled to Syria and Iraq may return to commit further atrocities.
Ms Le Pen wants to cut immigration and restrict nationality rights, as well as hold a referendum on EU membership. She has accused her rival of being weak on terrorism
Mr Macron is pro-European and has said he favours strong external EU borders.