Grammarly

Grammarly is an AI-powered writing assistant used by over 30 million daily active users and 70,000 professional teams worldwide. Founded in 2009 by Alex Shevchenko, Max Lytvyn, and Dmytro Lider, the company has grown from a grammar-checking tool into a comprehensive AI communication platform valued at approximately $13 billion.

Grammarly's AI goes far beyond grammar and spelling correction — the platform provides real-time suggestions for tone, clarity, engagement, and delivery across emails, documents, social media posts, and messages. GrammarlyGO, the company's generative AI feature, can draft, rewrite, and reply to content in the user's personalized voice. The platform works as a browser extension, desktop app, keyboard, and integration across popular tools including Google Workspace, Microsoft Office, Slack, and Notion.

Grammarly's enterprise product includes custom style guides, brand tone enforcement, and knowledge-base integration that ensures AI suggestions align with organizational communication standards. The company's massive usage data (processing billions of text suggestions daily) provides a strong moat — its understanding of how humans write and communicate in professional contexts is derived from more real-world writing data than almost any other company.