The 23-year-old is reported to have declared himself a “nationalist” and wrote on an internet chatroom he wished to buy a Kalashnikov-type weapon to carry out a “political act”.
He was arrested in the Argenteuil suburb of Paris and taken into custody on Thursday, where he told police of his plans to harm Mr Macron and “Muslims, Jews, blacks, homosexuals” at a 14 July celebration in the French capital.
The man, said to be unemployed and influenced by far-right ideology, was given preliminary charges of individual terrorist activity on Saturday.
A spokeswoman for the Paris prosecutor’s office said on Monday the suspect’s plans were vague and not yet finalised, while he appeared to be acting alone.
According to RMC Radio, it was the man’s comments on a website linked to a video game – in which he revealed his search for a powerful assault rifle – that alerted police to his planned attack.
He is alleged to have threatened police with a kitchen knife as he was arrested.
According to the report, he has previously been convicted for condoning terrorism.
The French president is due to attend the annual military parade along the Champs-Elysees and Arc de Triomphe in Paris on Bastille Day together with US President Donald Trump.
In 2002, far-right supporter Maxime Brunerie tried to assassinate former French president Jacques Chirac with a rifle at the Bastille Day parade.
He fired one shot before bystanders overpowered him.
Mr Macron won the French presidency in May after seeing off the challenge of National Front candidate Marine Le Pen.