The app with the new changes is available through the iTunes App Store for iOS devices and the Google Play Store for Android devices. The video feature has not been implemented for all Android handsets, however.
Vine, which launched in January, has 13 million users and lets people create and share six-second video clips. Instagram has 100 million users, up from 20 million when Facebook bought the company more than a year ago. If users like it, Facebook's move could propel mobile video sharing into the mainstream.
To use the video feature, Instagram users can tap on the same camera icon they use to snap photos. A new video camera icon will appear on the right side. Tap it and a screen with a red video button will let you record clips of sunsets, kids running in parks or co-workers staring at their computer screens.
The app will record as long as the user's finger is on the red button or for 15 seconds, whichever comes first. Not unlike Vine, taking your finger off the button will stop the recording, allowing you to shoot the scene from a different angle or record something else altogether. Once you have 15 seconds of footage, you can play it from the beginning and post it on Instagram to share with others.
Given Vine's popularity, "it is perhaps more surprising that Facebook has not introduced video for Instagram sooner," said Eden Zoller, principal consumer analyst at Ovum, a technology research firm. "There is no doubt Twitter will move quickly to up the ante on Vine and this could undercut Facebook's efforts with video on Instagram."