The range of new features
were revealed at the global launch in New York, including a dual camera function that can take two pictures at once and "smart pause", which lets users pause a video by looking away from the screen.
"We have taken technology and innovation forward to help us get closer to what matters in life, to help us live a richer, simpler and more full life," said JK Shin, president and head of IT and mobile communications at Samsung.
The highly-anticipated smartphone is predicted to pose a major threat to Apple and its dominance of the US market.
But investors have largely shrugged off the launch. Shares in Samsung were 2.3% lower in Seoul on Friday.
The device will be on sale in the UK from April 26, and will be available through 327 mobile operators in 155 countries, including Orange, EE and Vodafone.