Once-great social media and blogging platform Tumblr has gone through a number of big changes in recent years, and another one is right around the corner. Parent company Automattic says it is migrating all Tumblr blogs—more than half a billion in number—to the WordPress back end.

In a blog post announcing the initiative this week, Automattic is careful to note that it doesn't want anything about the front-end user experience of Tumblr to change. We love Tumblr’s streamlined posting experience and its current product direction. We’re not changing that," a rep wrote.

In terms of user experience, the two blogging platforms have very different emphases. WordPress is meant to be powerful, customizable, and extensible to serve a variety of needs, while Tumblr is meant to streamline the experience to be something like a middle ground between operating a WordPress blog and using something like X or Threads.

The plan is to move to the WordPress back end so that Automattic can develop features that will deploy to Tumblr and WordPress blogs simultaneously. This will let Tumblr tap into the robust existing WordPress.com infrastructure and allow the open-source work happening on WordPress to more easily be tapped to improve Tumblr.

The Automattic post did not provide a timeline; it simply acknowledged that this will be "one of the largest technical migrations in Internet history."

Automattic acquired Tumblr in a humbling fire sale of just $3 million—a far cry from the $1 billion the platform was worth to Yahoo not all that many years ago. Yahoo acquired Tumblr then to try to turn it into a Facebook competitor, but it consistently failed to make the right choices to make that happen—if it even possible.

Since the acquisition, Automattic has shuffled around employees and resources, including moving many off of Tumblr to other projects, but it says it plans to continue supporting Tumblr with new features in the future and that this migration is part of those plans.