Grammarly is an AI writing assistant with over 30 million daily active users. It operates as a browser extension, desktop app, and Microsoft Office add-in, checking writing in real time across email, documents, social media, and web forms.
The free tier covers basic grammar and spelling correction. Pro at $12/month adds advanced suggestions for clarity, conciseness, tone, and style. AI rewriting tools generate alternative phrasing and full-sentence rewrites on demand.
Grammarly’s broad deployment is a key advantage. Unlike document-specific tools, it works inside Gmail, Outlook, Google Docs, Notion, LinkedIn, Slack, and most web applications simultaneously.
The plagiarism checker in Pro compares text against over 16 billion web pages — useful for content teams who want to verify originality before publishing.
The Business plan was discontinued in 2025. Enterprise is now available through Grammarly for Business requiring sales contact.
The main limitation is contextual accuracy — Grammarly can flag correct and intentional writing choices, particularly in technical writing. The Pro plan auto-renews without an advance reminder.