Grammarly writes a new corporate playbook

When San Francisco cybersecurity company HackerOne got serious about its written communications, its concerns went far beyond pesky split infinitives. For example, much of its messaging is aimed at hackers—not online criminals, but the kinds of ethical geeks who bristle at the use of the term “hacker” to describe the bad guys. To make sure it didn’t inadvertently tick off this critical audience through any sloppy phrasing or poor word choices, the company gave more than 50 employees their own writing coach: Grammarly.

Famous—or maybe infamous—for its omnipresent YouTube ads, Grammarly has transcended the mandate implied by its name. Increasingly, the AI-infused service is helping companies fine-tune how their staffers write, expanding to “the style preferences that companies might have, the brand tones they prefer, the vocabulary they use,” says Grammarly CEO Brad Hoover.

Thirteen years ago, Grammarly was a Kyiv-based fledgling that was known as Sentenceworks and expected students rather than corporate employees to be its primary audience. In 2010, when its Ukrainian cofounders Max Lytvyn, Alex Shevchenko, and Dmytro Lider met Hoover—at the time, a Grammarly fan who also happened to be a venture capitalist—they soon concluded that he should be the CEO, and they should focus on product, technology, and revenue. That led the startup to relocate its headquarters to San Francisco in 2012. (In the wake of Russia’s invasion of Ukraine, Grammarly, which says it still has “many” employees there, has committed $5 million in aid for the Ukrainian people.)

A decade later, more than 30 million people and 30,000 teams use Grammarly’s free and paid versions. With a $200 million funding round last November, the company hit a valuation of $13 billion. CB Insights ranked it as the 10th most valuable U.S. startup; Pitchbook said it had become the most valuable natural-language AI company in the world, period.