Google is experimenting with a new feature that allows marketers, media companies, politicians and other organizations publish content directly to Google and have it appear instantly in search results.

The search giant said it began testing the feature in January and has since opened it up to a range of small businesses, media companies and political candidates.

Fox News has worked with Google to post content related to political debates, for example, while People.com published posts related to the Oscars in February. Earlier this week, HBO published “news” articles related to fictitious characters in its popular show “Silicon Valley” to promote the season 3 premiere.

A content carousel for HBO’s Silicon Valley on a Google search results page Photo: Google for The Wall Street Journal

Google has built a Web-based interface through which posts can be formatted and uploaded directly to its systems. The posts can be up to 14,400 characters in length and can include links and up to 10 images or videos. The pages also include options to share them via Twitter, Facebook or email.

Each post is hosted by Google itself on a dedicated page, and appears in a carousel in results pages for searches related to their authors for up to a week, a Google spokeswoman said. After seven days, the posts remain live but won't be surfaced in search results. Rather, they can be accessed via a link.

“We’re continuing to experiment with the look and feel of this feature, including exploring other potential use cases,” according to a statement from Google. A Google spokeswoman said the feature doesn’t yet have an official name.

On Thursday morning, searches for “Jimmy Kimmel” returned a carousel featuring multiple posts created by the show’s producers, for example. One of those posts, published Monday, featured a YouTube video clip of Mr. Kimmel naming babies live on his show.

Cricket-focused sports site Cricbuzz appeared to be extremely active on the feature, posting to it around every 10 minutes on Thursday morning.

A Cricbuzz content carousel on a Google search results page Photo: Google for The Wall Street Journal

The Google spokeswoman said the experimental feature is separate from Google’s Accelerated Mobile Pages program, which aims to speed up online content by streamlining the code that powers Web pages.

With the AMP program, Google also “caches” pages, or saves copies of them on its own systems, in order to deliver them more quickly to users. AMP doesn’t host content directly, however, whereas Google’s new search feature does.

Google’s tests of the new posting tool comes at a time when media companies, marketers and organizations of all types are increasingly distributing content by publishing directly to major online platforms, instead of driving users back to their own websites and properties.

Facebook has an Instant Articles feature, for example, which lets anyone host their content directly on the social network, provided they adhere to its content policies. Facebook also overhauled its own “Notes” feature in September 2015 which—similarly to Google’s new feature—offers a Web interface through which users can publish their content directly to the social network.

Apple also unveiled a Web-based publishing tool that allows users to arrange and publish content directly to its Apple News application.

The Google spokeswoman emphasized that the new tool remains in an experimental phase, and wouldn't provide details on if or when it may be opened up to more authors. Google is currently testing it with a range of different type of partners, she said, but wouldn't disclose exactly how many.

A Web page promoting the feature currently describes it as invite-only and encourages interested parties to join a waitlist.

Write to Jack Marshall at Jack.Marshall@wsj.com