Grammarly

Grammarly is the most widely adopted AI writing assistant, used by over 30 million people daily to improve their writing across emails, documents, and messages. Unlike content generators, Grammarly focuses on enhancing existing text — correcting grammar and spelling errors, improving sentence clarity, adjusting tone, and ensuring consistency.

Its real-time suggestions appear directly in the browser, desktop apps, and mobile keyboards, making it effectively invisible once installed. Grammarly's tone detector analyzes whether your writing comes across as formal, friendly, confident, or other qualities, helping professionals match their intended communication style.

The Business tier adds a style guide feature where organizations define company-specific terminology and writing rules that all team members follow. Grammarly recently introduced GrammarlyGO, a generative AI layer that can rewrite paragraphs, compose drafts, and generate replies based on context.

What distinguishes Grammarly from ChatGPT-style tools is its focus on accuracy and refinement rather than generation from scratch, making it a complement rather than a competitor to AI content generators.