Grammarly Inc. today announced plans to acquire Superhuman Labs Inc., a venture-backed startup with a popular email client, for an undisclosed amount.

San Francisco-based Grammarly provides an artificial intelligence writing assistant of the same name. It can fix spelling and grammatical errors, rewrite sentences and generate new text from scratch. Grammarly says its installed base includes about 40 million users across more than 500,000 organizations.

The popularity of the company’s software has helped it raise more than $1.5 billion in funding to date. About two-thirds of that capital was provided by General Catalyst through a deal announced in May. Grammarly didn’t sell shares, but instead committed to paying back the investment along with a percentage of the sales it generates using the funds.

General Catalyst’s cash infusion likely made it simpler to finance the Superhuman acquisition. The latter company received a $850 million valuation in 2021, which suggests the purchase price may have been significant. According to Reuters, Superhuman currently generates $35 million in annual revenue.

The company’s eponymous email client works with Gmail and Outlook. It provides dozens of shortcuts designed to help users navigate message archives more efficiently. Integrations with customer relationship management, or CRM, platforms allow salespeople to access deal data without leaving the interface.

Earlier this year, Superhuman refreshed its email client with a set of AI-powered productivity features. It can now automatically group messages by category and archive low-priority correspondence. Furthemore, the update brought text generation capabilities similar to the ones offered by Grammarly.

AI will become a bigger focus following the acquisition. According to Grammarly, the plan is to equip Superhuman with AI agents that can automate tasks such as rewriting emails. The company says that those agents will also be capable of interacting with one another and third-party systems. 

“By joining forces with Grammarly, we will invest even more in the core Superhuman experience, as well as create a new way of working where AI agents collaborate across the communication tools that we all use every day,” said Superhuman Chief Executive Officer Rahul Vohra.

The acquisition is part of an effort on Grammarly’s part to become a “multi-product company.” The initiative previously saw it acquire a venture-backed startup called Coda last year. Coda developed an AI-powered word processor that can be used to create documents, spreadsheets and knowledge base articles.

The capital that Grammarly raised from General Catalyst in May could allow it to make more acquisitions. According to Reuters, the company also plans to rebrand as part of its push to branch out into new product categories. 

Image: Superhuman