American educator Salman Khan and his Khan Academy online platform that offers free classes worldwide have won Spain's Princess of Asturias award for international cooperation.

The Khan Academy's videos on YouTube have been watched more than 1.4 billion times since the project launched in 2008. It has around 60 million registered users.

There are English, Spanish, French and Portuguese versions of the site, and its resources are translated into more than 36 languages.

Prize organizers announced Wednesday that Khan and his innovative work have created "an original and transformative format offering free educational materials ... for all ages, anywhere in the world."

The 50,000-euro ($55,000) annual award is one of eight Asturias prizes handed out yearly by a foundation named for Crown Princess Leonor. Others categories include art and sports.