The interior ministry said roughly 800,000 people protested, whereas the CGT trade union put their estimate at 1.5 million.
A nationwide strike on Thursday, December 5th brought France to a near standstill as demonstrators marked their opposition to the pension reform project led by the government of Emmanuel Macron.
France's interior ministry said roughly 800,000 demonstrators protested on Thursday, but one of the largest trade unions in France, the CGT, put the number at around 1.5 million.
The discontent was particularly palpable among education workers - roughly 40-50% of them were on strike according to the education ministry - and in transportation as 90% of trains were cancelled.
But how does this mobilisation compare to others?
This past mobilisation isn't over yet.
Unions have called for people to continue striking - with Tuesday, December 10th as the next national mobilisation against retirement reform.
Trade union Force Ouvrière said the strike was "of rare scope, unprecedented since 2010 and 1995".
Over the past 20 years, the French have come out in droves to express their opposition to changes in retirement.
The year 2010 was marked by several large protests against the measures of Prime Minister François Fillon's government concerning a gradual rise in the statutory retirement age.
One of the largest social movements in French history took place in December 1995 when over the course of three weeks, millions of workers protested Prime Minister Alain Juppe's plans for social security and pensions.
The objective of this project was to apply private sector measures from 1993 to civil servants and public companies such as rail.
France, world leaders in strikes?
France is often perceived as a country where strikes are frequent, but it's difficult to quantify the number of people who strike on a given day.
Yet data from two French government directorates on the number of individual days not worked due to strikes and the number of days lost due to strikes appear to show a decline in striking in the country.
This could be due to a decline in union membership in France. Less than 10% of French workers are members of unions.
The European Trade Union Institute also offers some data on strike movements in different countries all while noting that there is different sourcing in countries, making it difficult to compare.
Their study shows nonetheless that Cyprus, Spain, and Greece also have their fair share of strikes.