In France, if you deny the Holocaust, you might get prison time between 1-5 years and a fine.
In France, the Gayssot Act, voted for on July 13, 1990, makes it illegal to question the existence of crimes that fall in the category of crimes against humanity as defined in the London Charter of 1945, on the basis of which Nazi leaders were convicted by the International Military Tribunal at Nuremberg in 1945-46. When the act was challenged by Robert Faurisson, the Human Rights Committee upheld it as a necessary means to counter possible antisemitism. In 2012, the Constitutional Council of France ruled that to extend the Gayssot Act to the Armenian Genocide denial was unconstitutional because it violated the freedom of speech.
LAW No 90-615 to repress acts of racism, anti-semitism and xenophobia (1990)
MODIFICATIONS OF THE LAW OF JULY 29, 1881 ON THE FREEDOM OF THE PRESS Art 8. – Article 24 of the Law on the Freedom of the Press of 29 July 1881 is supplemented by the following provisions: In the event of judgment for one of the facts envisaged by the preceding subparagraph, the court will be able moreover to order: Except when the responsibility for the author of the infringement is retained on the base for article 42 and the first subparagraph for article 43 for this law or the first three subparagraphs for article 93-3 for the law No 82-652 for July 29, 1982 on the audio-visual communication, the deprivation of the rights enumerated to the 2o and 3o of article 42 of the penal code for imprisonment of five years maximum;
Art 9. – As an amendment to Article 24 of the law of July 29, 1881 on the freedom of the press, article 24 (a) is as follows written: <<Art. 24 (a). – those who have disputed the existence of one or more crimes against humanity such as they are defined by Article 6 of the statute of the international tribunal military annexed in the agreement of London of August 8, 1945 and which were a carried out either by the members of an organization declared criminal pursuant to Article 9 of the aforementioned statute, or by a person found guilty such crimes by a French or international jurisdiction shall be punished by one month to one year’s imprisonment or a fine.
Art 13. – It is inserted, after article 48-1 of the law of July 29, 1881 on the freedom of the press, article 48-2 thus written: <<Art. 48-2. – publication or publicly expressed opinion encouraging those to whom it is addressed to pass a favourable moral judgment on one or more crimes against humanity and tending to justify these crimes (including collaboration) or vindicate their perpetrators shall be punished by one to five years’ imprisonment or a fine