Leading universities will offer fully accredited undergraduate courses online within five years, says the co-founder of a US online university network.
Daphne Koller, president of Coursera, said the necessary technology was available but universities had been hesitant about their "reputation".
So far, online courses have mostly offered certificates for short courses rather than full degrees.
Prof Koller says online degrees can be "more affordable and accessible".
Founded in California four years ago, Coursera has become one of the world's biggest providers of "massive, open, online courses" - known as Moocs.
The online platform has 20 million students following courses from about 145 prestigious universities and institutions around the world. But most of the online courses have been short units that give students a certificate, rather than a full degree or credits towards a degree.
Prof Koller, speaking at an educational technology conference in London, said the next stage for online learning would be leading universities offering mainstream undergraduate courses online, with invigilated exams and full degrees.
