Automattic CEO calls Tumblr his ‘biggest failure’ so far

WordPress co-founder and Automattic CEO Matt Mullenweg called the company’s Tumblr acquisition his biggest failure — but one he hasn’t given up on yet. The comments were made at the recent WordCamp Canada 2025 conference, where Mullenweg went live for a Town Hall session to connect with the open source-focused WordPress community.

The exec noted that Tumblr was still on a different technical stack than WordPress — something he had intended to correct by migrating the back end to WordPress infrastructure. However, that massive undertaking was put on hold earlier this year, as the cost to move Tumblr’s half a billion blogs would be difficult given that the blogging platform wasn’t profitable and continues to be sustained by the profits of other Automattic products.

The company has tried to trim costs with layoffs and the reallocation of Tumblr resources to more profitable parts of the business, but those efforts have yet to pay off.

Mullenweg acknowledged these concerns at his Town Hall session, saying, “I need to switch [Tumblr] over to WordPress, but it’s a big lift. It’s over 500 million blogs, actually, and, as a business, it’s costing so much more to run than it generates in revenue.”

As a result, Automattic had to prioritize other projects to make Tumblr sustainable, he said.

“It’s probably my biggest failure or missed opportunity right now, but we’re still working on it,” he added.

If Tumblr were to move to the WordPress back end, it would be simpler and more cost effective to maintain. Plus, it would enable the service to further join the open social web known as the fediverse, which was to be one perk of the WordPress migration.

During the course of his talk, Mullenweg discussed the other projects underway at the company, including at WordPress, Jetpack, and WooCommerce. He mentioned, Playground, which lets you run WordPress entirely in a web browser and Automattic’s universal messaging app Beeper. The latter will be expanding to include support for bridges to other messaging apps, like KakaoTalk and messaging services from dating apps, he said.

He also touched on AI, saying “we’re not putting the genie back in the bottle” with the technology, and calling companies like OpenAI “too big to fail.” In one area of the business, the WordPress theme directory, he’s thinking of tagging images made with AI to allow people to filter their searches appropriately, rather than rejecting AI-generated themes.

Notably, Mullenweg answered a question about the legal drama with WP Engine, a WordPress hosting company that Automattic has called out for profiting from the open source ecosystem without giving back. In response to an audience question about bad actors who exploit the community, Mullenweg responded that he didn’t “want to say that there’s bad actors,” but rather “bad actions.”

He suggested that Automattic should create more incentive systems to encourage contributions and other good behavior, like giving certain people higher rankings in the WordPress directory or showcase. He also encouraged the community to “vote with your wallet” by not supporting businesses that aren’t doing the right thing.

“There’s a site called WordPressEngineTracker.com which is currently tracking a number of sites that have left a certain host. It’s about to cross 100,000 … that have switched to other hosts, and there were 74,000 have gone offline since September of last year,” he said.

The court ordered the site taken down at one point, which Mullenweg told the crowd was them “trying to muzzle free speech and transparency.”