The average Instagram user misses 70 percent of what’s in their feed, including great photos with tons of Likes and posts by their best friends. So today Instagram announced it will start rearranging the order of posts in its feed. Rather than strictly reverse chronological, Instagram will order posts “based on the likelihood you’ll be interested in the content, your relationship with the person posting and the timeliness of the post.”

The testing will start out slowly; at least at first “all the posts will still be there, just in a different order.” But eventually, low-quality posts might be filtered out entirely.

The changes mean if you don’t check your feed until the next morning but a friend whose photos you usually Like posted something awesome the night before, it could appear at the top of your feed even if it is hours old. This is essentially how Facebook’s feed works, and how Twitter recently reconfigured its feed to work.

On the one hand, the relevancy-optimized Instagram feed will make sure you don’t miss great content even if you don’t neurotically check it all the time. You’ll be able to follow more accounts without worrying about them drowning out your favorites. And it will be easier to keep up with international friends who might normally post while you’re asleep.

At the same time, remixing the feed will make Instagram less useful as a real-time content feed because the most recent posts won’t necessarily be at the top. Users will have to worry about making their posts good enough to be chosen by the algorithm or their posts could be de-prioritized. And brands might lose the reach of a previously reliable marketing channel, the same way they did with Facebook Pages.

Filtered feeds tend to score more attention from users, as there are few boring posts that push them to close the app and do something else. And at this point, Instagram is so ingrained in people’s lives that they’re unlikely to ditch it over this change. But with Instagram and Twitter both moving to algorithmically sorted feeds, getting seen on social media will become more of a competition than ever.