The two, aged 10 and three, were unharmed by the fall on Tuesday but might have suffered from smoke inhalation, French media reported.
Video of the dramatic rescue showed the younger brother being dropped from at least three storeys up as black smoke billowed from the window and flames engulfed an adjacent balcony.
As onlookers screamed, the older brother then hung from the window and let himself fall into the arms of those below.
The boys were taken to hospital along with 17 residents of the building, the media reports said.
Four of the people who caught the boys were also taken to hospital to check if any bones were fractured when they caught the boys.
Athoumani Walid, a 25-year-old student who suffered a broken wrist from helping catch the children, said he heard screams and went out to investigate after seeing the fire from his nearby apartment and rushed to help along with four or five other people.
“We didn’t know what to do,” Mr Walid said.
“We wanted to break the door but it wasn’t possible.”
They then went outside and shouted for the boys to jump into their arms, he said.
Although he initially feared for the boys, “when they jumped, fear disappeared”, Mr Walid said.
“What mattered was to catch” them, he added.
Mr Walid said he hopes the rescue will change perceptions of the Villeneuve neighbourhood, which has a large immigrant population.
“We are told it’s a ‘sensitive’ neighbourhood,” he said, “but yesterday we showed we are here for each other, and we save each other.”
Mayor Eric Piolle congratulated residents on the rescue, which he said underscored the city’s “tradition of solidarity and mutual help”.
In May 2018, a young Malian migrant rescued a child dangling from a balcony and was offered French citizenship.
Video of the rescue showed 22-year-old Mamoudou Gassama climbing up four floors of the apartment building in just seconds to rescue the child, to cheers from onlookers.
By the time Parisian emergency services arrived, he had already pulled the child to safety.
