Grammarly is an AI-powered writing assistant founded in 2009 that has evolved from a basic grammar checker into a comprehensive communication platform with generative AI capabilities. With over 40 million users and 50,000 organizations, Grammarly provides real-time grammar checking, tone detection, clarity improvements, plagiarism detection, AI content detection, and generative AI writing through its GrammarlyGO feature. 1)
Grammarly was founded in 2009 as a subscription product to help students correct spelling and grammar. 2) Over more than a decade, the company built its reputation on core spelling, grammar, and style guidance delivered through browser extensions, desktop apps, and mobile keyboards. By March 2023, the platform had grown to serve 30 million daily users and over 50,000 teams. 3)
In March 2023, Grammarly launched GrammarlyGO, a suite of generative AI writing and editing tools that expanded the platform beyond revision into content conception and composition. 4) GrammarlyGO began rolling out in beta in April 2023.
GrammarlyGO is built on OpenAI's GPT-3-derived API for generative capabilities, while Grammarly maintains its own proprietary algorithm for core spelling and grammar corrections. 5) By 2026, the platform utilizes advanced Large Language Models and context-aware NLP architectures. 6)
GrammarlyGO provides the following generative AI features: 7)
Grammarly analyzes writing tone across multiple dimensions, detecting whether text sounds confident, friendly, formal, diplomatic, constructive, or other qualities. By Fall 2023, an automatic voice profile feature was introduced that describes the unique elements of a user's writing style, allowing one-click rewrites to match that voice. 8)
Beyond generative AI, Grammarly provides: 9)
Grammarly Business and Enterprise tiers offer: 10)
Grammarly operates as an overlay across virtually every writing context: 13)
As of 2026, Grammarly offers three tiers: 14)
| Plan | Monthly | Annual (per month) | AI Prompts | Key Features |
|---|---|---|---|---|
| Free | $0 | $0 | 100/month | Basic grammar, spelling, tone detection, conciseness | |
| Pro | $30/mo | $12/mo | 2,000/month | Full grammar/style/clarity, plagiarism detection, AI detection, full-sentence rewrites | |
| Enterprise | Contact Sales | Contact Sales | Unlimited | Everything in Pro plus style guides, brand tones, admin panel, SAML SSO, BYOK encryption |
In late August 2023, Grammarly launched features designed to help professors uphold academic integrity while preparing students for AI-augmented work. These features guide students in leveraging generative AI to augment rather than replace critical thinking. 16)