President Emmanuel Macron has announced compulsory schooling in France will begin at age three, instead of six, as part of new reforms set to shake up the country's education system.

"Kindergarten will be a founding moment in our school journey," Mr Macron said in his announcement on Tuesday.

"I decided to make kindergarten compulsory and thus to lower the age of schooling from six to three years," he said.

On paper, this ruling will only affect a small minority, with 2017 OECD figures showing at least 95 per cent of three-year-old children are already enrolled in pre-primary school education programs.

However, this percentage is not evenly spread across France and its territories. A higher percentage of three-year-old children attend pre-primary education programs compared to children in Corsica and France's overseas territories.

In announcing his reforms, Mr Macron said the change to make early education compulsory was intended to curb education inequality, as parents in poorer areas of France and in overseas territories were less likely to send their children to school at an early age.

Mr Macron also said the reform aimed to prevent school dropouts because it would eliminate inequality in learning the language.

"I want to pursue the work of equality and progress in our educational history," Mr Macron said.

"Compensating for education inequality from birth is within our grasp."

Following his announcement, Mr Macron took to Twitter to continue spruiking his reform.

"Because there is still too much tendency to confuse nursery school and day care, compulsory schooling from three years is a real change of mindset," he tweeted.

Annually, France spends 0.8 per cent of its GDP on pre-primary education — above average across the OECD.

Australia is well below the OECD average of investment in early childhood education, as well as the number of young children who access pre-school education.

The latest Programme for International Student Assessment (PISA) for France showed attendance to an early education or pre-school structure, for at least one year if not two, provided a strong foundation to support students through school later on.

Many other OECD countries have also moved towards integrated systems of preschool care for children under six, a holistic approach that helps ease the preschool to school transition.