Snap launched a new search function Friday in an effort to make all the content created by its users far more accessible.

This opens up the massive amount of content that Snapchat has drawn from its 158 million users to contribute to its "Stories" feature, which launched in October 2013. The company is using advanced machine learning to evaluate caption text, time and visual elements, to create new stories out of those Snaps.

"We've built a new way to understand what's happening in Snaps that are submitted to Our Story, and to create new Stories using advanced machine learning. The results have been amazing: you can search over 1 million unique Stories on Snapchat," the company wrote in a blog post.

The "Stories in Search" feature will roll out starting Friday in select cities. While there's no mention of advertising, introducing search clearly opens up a whole new ad category for Snap. As we've seen with Google, as well as Facebook and Twitter, which have search functionality, search provides valuable information to help target ads.

With analysts asking questions about how Snap will grow its revenue, this is a key step toward making the app more useful, while opening the door to a new type of advertising.

Disclosure: CNBC parent NBCUniversal is an investor in Snap.

