Education minister Luc Ferry announced plans to set up internet filters in state schools to prevent pupils viewing websites with anti-Semitic and other race-hate messages before this week's cabinet reshuffle.
It is the third school measure unveiled in recent weeks aimed at defusing rising inter-community friction.
A fortnight ago Mr Ferry launched a Republican Guide for teachers to help promote anti-racism, tolerance, integration and the Republic itself.
Last month the controversial law banning religious signs in schools was adopted, but it has already been challenged by a young girl in a coll ge (lower secondary school) who turned up for class in a headscarf, to the fury of staff who then went on strike.
Anti-Semitism in France, which is home to western Europe's largest Jewish and Muslim populations, has become a major concern for the cabinet.
"The rise in anti-Semitism in schools is a particularly worrying phenomenon, one that faces students at an earlier and earlier age," prime minister Jean-Pierre Raffarin said.
Last week Mr Ferry said schools will receive software for their servers that will screen out a list of hate sites that is to be updated daily.
An umbrella group for Jewish organisations, the Representative Council of Jewish Institutions of France (CRIF), is to provide information to the education ministry on combating anti-Semitic messages in particular.
Internet service providers, CRIF and a police arm responsible for combating online crime, are to be directly linked via the internet so that authorities can be quickly notified about suspected criminal activity. The Republican Guide was due out in November, but its launch was postponed to coincide with the new law on religious symbols in schools.
Available at www.education.gouv.fr, it will be finalised after feedback from teachers and distributed to all coll ges and lycees (upper secondary schools) by June. It includes 30 ideas from intellectuals such as Elizabeth Badinter, Pascal Bruckner and Regis Debray.
Republican values - liberty, equality and fraternity - are a leitmotiv in France and supposedly form the bedrock of French society. The booklet also includes an anthology of poems, songs, film texts and poignant letters written during the Second World War as subjects of debate in class.
In an interview with the daily newspaper Le Parisien, Mr Ferry said neither current civics education on morals nor lessons on constitutional law are appropriate, when in reply to the question "what do you like?"
comes "I like football, but not Jews."
The problem varies considerably from one establishment to another, but probably involves only 4 to 5 per cent of the total, he said. In these cases, insults like "dirty Jew" or "dirty Arab" have become so frequent that headteachers prefer to ignore them.
Mr Ferry was set to be replaced as education minister on Wednesday by Francois Fillon in a government reshuffle triggered by the ruling centre right's disastrous results in regional elections.