Facebook introduced Instant Articles this Spring. Source: Facebook.

More and more people are accessing the Internet through mobile devices. Facebook (NASDAQ:FB), for example, sees nearly 90% of its users access its site via mobile devices and 44% access Facebook solely through their mobile devices. That's why Facebook developed Instant Articles, a publishing format that it hosts on its servers to load content extremely quickly.

Google (NASDAQ:GOOG) (NASDAQ:GOOGL) and Twitter (NYSE:TWTR) seem to think that's a pretty smart idea, and Re/Code reports the tech companies are working on their own version of Instant Articles. There are several key differences in their methods compared to Facebook's, but the core concept is the same -- make articles load faster on mobile devices. The feature is reportedly set for release this fall with limited partners and should provide Google and Twitter some ammo to keep up with Facebook.

An increasingly mobile user base
Earlier this year, Google announced that more searches come from smartphones and tablets than laptops and desktops. Smartphones account for more than half of searches in 10 countries, including the U.S and Japan.

Twitter, meanwhile, has always been a mobile-first product, developed with standard SMS messaging in mind (hence the 140-character limit). A total of 88% of the company's ad revenue came from mobile during the second quarter.

Both of these companies rely on displaying and linking to other people's content, so the more efficiently they can do that, the more useful they become.

Facebook, however, has become the top referrer to news sites, according to analytics company parse.ly. That lead is expected to grow as Facebook makes efforts to attract more publishers and individual journalists to its platform.

On mobile, Facebook is even more dominant. It takes up about 20% of time spent on mobile. Instant Articles are specifically designed for mobile and provide more of a native app feel than the mobile browser built into apps such as Facebook, Twitter, and Google's Search app. Google and Twitter needed to respond to Instant Articles in order to maintain their positions with publishers.

Why publishers might choose Google and Twitter over Facebook
Although Facebook refers tons of traffic to publishers, there's some pause when it comes to working with Facebook and its Instant Articles.

First of all, Facebook's Instant Articles require publishers to let Facebook host the content on its servers. That allows Facebook to ensure the article loads quickly. Google and Twitter's solution uses cached websites to reduce bandwidth usage. This allows articles to load quickly and for websites to maintain control over their content.

That distinction is particularly important for Google, which is facing antitrust allegations that it's directing users to more self-hosted content than content from other publishers. Twitter, likewise, will soon unveil its Project Lightning feature, which is designed to showcase top content from Twitter without linking to outside sources.

Another difference between Google's and Twitter's reported solutions and Facebook's is that the formers' will be open source. They hope other tech companies will adopt the solution as well, which would improve its usefulness across all platforms, including their own. What's more, widespread adoption could make Facebook's Instant Articles a nuisance for publishers rather than a feature.

A reactionary product
The fact that Google and Twitter were compelled to create their own version of Instant Articles is indicative of Facebook's innovation with mobile. Facebook continues to set the direction of the mobile Internet, and Google and Twitter simply follow its lead. That innovation coupled with Facebook's sizable and highly engaged audience make it the front-runner to attract digital ad spend over Google and Twitter.