SAN FRANCISCO, United States — Instagram introduced a new mobile application called Threads that will allow users to stay in close contact with a small circle of people, automatically sharing videos and statuses with them.

The separate messaging app will help Instagram, which has more than 1 billion users, combat one of the inevitable side effects of growth — the loss of intimacy for users. The more people on an app, the bigger their audience, and the less they want to share about their lives with the wider group. Facebook Inc., which owns Instagram and is larger, has faced the same problem for years.

Instagram’s separate destination for more personal sharing also hits a long-time rival, Snap Inc., the maker of Snapchat, which declined as much as 7.6 percent on the news. In 2016, Instagram copied Snapchat’s popular “stories” product for posting photo and video updates that disappear. To remain distinctive, Snap has since focused its app on emphasising messaging with close friends and has positioned itself as the fastest way to share with them. Snapchat had an average of 203 million daily users in the three months ended in July.

Now Instagram is targeting Snapchat’s audience again. Threads “is the fastest way to share a photo or video with your close friends on Instagram,” the company said Thursday in a blog post. “It opens directly to the camera and allows you to add shortcuts, so you can share what you’re doing in just two taps.”

Like Snapchat’s map feature, Threads can give an automatic update about what users are doing, but without placing them on an actual map. Instead, it will use location information to explain whether someone is at the beach, driving, or at a coffee shop, without giving the name of the shop. Threads will also let friends know whether a users’ phone is on low battery.

Instagram said these choices are meant to take some of the effort out of keeping in touch with people all day, but still keep them informed. They’re also a response to the privacy concerns around Facebook. Instagram thinks people will share intimate details online, but with a smaller audience than their regular account.

By Sarah Frier; editors: Jillian Ward, Andrew Pollack.