Grammarly

Grammarly is the most widely used AI-powered writing assistant, helping over 30 million daily active users improve their grammar, spelling, punctuation, clarity, and tone across virtually every platform where they write. Founded in 2009 by Alex Shevchenko and Max Lytvyn in Kyiv, Ukraine, Grammarly has grown from a simple grammar checker into a comprehensive AI communication platform valued at $13 billion. The tool works as a browser extension, desktop app, mobile keyboard, and integrates directly into Microsoft Office, Google Docs, and dozens of other applications. Its real-time suggestions appear as underlined text with one-click fixes, making it feel like having a copy editor looking over your shoulder at all times.

Real-Time Grammar and Spelling Corrections

At its core, Grammarly catches grammatical errors, misspellings, and punctuation mistakes with a high degree of accuracy. It goes beyond basic spell-check by understanding context — correctly identifying when "their" should be "there," catching subject-verb agreement issues in complex sentences, and flagging comma splices and dangling modifiers. The free tier covers these fundamental corrections across all platforms, making it immediately useful without any payment. For non-native English speakers, these real-time corrections are particularly valuable as a learning tool, since Grammarly explains why each change is suggested.

Clarity and Style Improvements

Premium subscribers get access to Grammarly's clarity and style engine, which rewrites wordy sentences, eliminates passive voice where active voice is stronger, and suggests vocabulary improvements. The tone detector analyzes your writing and labels it as formal, informal, confident, friendly, or other tones, helping you adjust your voice for different audiences. Full-sentence rewrites (powered by generative AI) can transform awkward sentences into polished prose while preserving your meaning. These features move Grammarly beyond error correction into genuine writing improvement.

GrammarlyGO: Generative AI Integration

GrammarlyGO is Grammarly's generative AI feature that can compose, rewrite, reply, and brainstorm text on demand. You can highlight a paragraph and ask GrammarlyGO to make it shorter, more formal, or more persuasive. It can draft email replies based on context, generate outlines for documents, and help overcome writer's block with suggested openings. Unlike standalone AI writing tools like ChatGPT, GrammarlyGO works inline within your existing documents and emails — you do not need to switch to a separate app. However, free-tier users receive limited monthly prompts, and the generative quality, while competent, does not match dedicated large language models for complex creative tasks.

Grammarly Business and Team Features

Grammarly Business ($15/member/month) adds team-level features: a style guide that enforces brand voice, terminology, and writing rules across all team members; an analytics dashboard showing team writing trends; snippets for reusable text templates; and centralized billing and user management. Companies like Cisco, Dell, and Expedia use Grammarly Business to maintain consistent external communications. The style guide feature is particularly powerful — you can define that "utilize" should always be "use," that your product name should always be capitalized a certain way, or that certain competitor names should never appear in outgoing communications.

Pricing and Limitations

The free tier is genuinely useful, covering grammar, spelling, and basic punctuation. Premium ($12/month billed annually) adds clarity, tone, vocabulary, plagiarism detection, and GrammarlyGO with more prompts. Business ($15/member/month) adds style guides and team management. Grammarly works best for English — it supports American, British, Canadian, and Australian English but does not support other languages (a significant limitation for multilingual teams). The browser extension can occasionally conflict with certain web applications, and some users report privacy concerns about sending all their text to Grammarly's servers for processing.