The 17-year-old, who cannot be named for legal reasons, was also the youngest person to be guilty of inciting racial hatred after setting up a website on which he showed a Ku Klux Klan lynching, when he was just 15.
He was given a two-year conditional discharge by magistrates after admitting distributing "threatening, abusive or insulting" material meaning to "stir" racial hatred, or being reckless as to whether racial hatred would result.
One video showed a black man being hanged by the Ku Klux Klan and then had his leg hacked off and thrown in to a fire, magistrates in King's Lynn, Norfolk, were told.
Defence lawyers for the youngster, who lives near Fakenham, Norfolk, said he had special needs and had been seeking attention.
But Viv Goddard, of the Crown Prosecution Service, said: "Young people need to realise that it is not a joke to post hate-filled material on video sharing websites or sites they set up themselves.
"The material in this case was not just offensive but highly disturbing in its violence and imagery, particularly one clip which showed a black man being hanged by the Ku Klux Klan then his leg being hacked off and thrown into a fire.
"People are entitled to hold racist and extreme opinions which others may find offensive and obnoxious."
The court was told it was second time the youngster had been convicted of computer misuse. Magistrates heard that in November 2008 he admitted "making" indecent images of children.
Prosecutors said the teenager had told visitors to his site they had to "swear and verify that I am of the white race".
On the site he described himself as "100%" Nazi and an "old-style racist".
Magistrates, sitting in a youth court, were told he had:
- Played "Benny Hill music" over images of malnourished African children.
- Posted a clip entitled "how to stab a n*****" on which he stabbed at a door covered in swastikas.
- Worn a black T-shirt with a slogan proclaiming "100% fascist" on a photograph he uploaded on to an internet site.
