Instagram is getting serious about video.

The fast-growing Facebook (FB) - Get Report -owned photo sharing site, now with over a billion users, launched a new longform vertical video platform called IGTV that will be available within Instagram as well as in a standalone app. Uploaded videos can now last as long as one hour, up from one minute previously. Alphabet's (GOOGL) - Get Report  YouTube and Snap (SNAP) - Get Report are potential rivals for IGTV.

"It's time for video to move forward and evolve," said Instagram CEO and co-founder Kevin System, saying that a new video service needed to be mobile first, simple and easy to discover quality content. Systrom launched the new platform at an event held in San Francisco and simulcast in other cities including New York. Instagram is courting creators to develop and publish content on the platform.

Systrom said the new IGTV app would be available in the coming days on Android and Apple app stores.

Facebook shares were rising 2.7% to more than $203 on Wednesday, a new all-time high. Alphabet shares were up 1.5% to 1,196.54 while Snap shares fell 3.3%.