Grammarly
: How to use it, features, and the business problems it solves
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What is Grammarly?
An AI writing assistant that detects and fixes grammar, spelling, and punctuation errors in English in real time. It also handles tone adjustment, rewriting, generative AI writing, and plagiarism/AI-text detection, usable broadly via browser extensions, desktop/mobile apps, and Microsoft Office and Google Docs. It is English-centric and effectively does not support Japanese proofreading.
Business problems it solves
About "Grammarly"
What is Grammarly
Grammarly is an AI writing assistant that detects and fixes grammar, spelling, and punctuation errors in English in real time. Under the banner "Think big. We'll take care of the details.," it has grown into an "AI writing partner" that also offers tone adjustment, rewriting, generative-AI writing, plagiarism and AI-text detection, and AI agents. It works across 1M+ apps and sites — browser extensions, apps, Microsoft Office, Google Docs.
Grammarly is strong at "English writing assistance," but effectively does not support Japanese proofreading. It handles grammar/spelling/punctuation, clarity/tone suggestions, rewriting/paraphrasing, generative AI (AI chat), plagiarism/AI detection, and citation generation. It also has agents like "AI Humanizer" and "AI Detector." The AI model used is not publicly disclosed.
A note on ownership: in 2025 the company acquired Coda and Superhuman (email), and the parent company was renamed "Superhuman" (Grammarly continues as its core product). The official site states "Grammarly is now a part of Superhuman," positioning an AI-native productivity platform. It is used by 40 million people and 50,000 organizations worldwide.
How to use
Refine the English you write, via extensions and apps.
Set it up
Enable the browser extension/apps or Office/Docs integration.
Write or paste
As you write English, it surfaces errors and improvements.
Fix & rewrite
Apply grammar fixes, tone adjustment, and rewrites.
Generate & detect
Draft with generative AI; run plagiarism/AI detection and citations.
The free plan includes grammar/spelling fixes and 100 AI prompts a month. Pro includes unlimited suggestions, rewrites, plagiarism/AI detection, and 2,000 AI prompts a month.
Key features
01Proofreading, tone, rewriting
Corrects English grammar, spelling, and punctuation, suggests clarity and tone, and rewrites/paraphrases sentences and paragraphs — suggesting in real time as you write.
02Generative AI, detection, citations
Supports prompt-based text generation (AI chat), plagiarism detection, AI-text detection, and citation generation. It also has agents like "AI Humanizer" and "AI Detector."
03Works everywhere
Usable via browser extensions, desktop/mobile apps, Microsoft Office, and Google Docs — across 1M+ apps and sites, wherever you work.
Pricing
You can start for free; the figures below are monthly. Plans differ by features and limits.
| Plan | Monthly | Main content |
|---|---|---|
| Free | $0 | Grammar/spelling fixes, tone display, 100 AI prompts/month |
| Pro | $12 | Unlimited suggestions, rewrites, plagiarism/AI detection, 2,000 AI prompts/month |
| Enterprise | By inquiry | Via Superhuman Go; org features |
Pro has a free trial. Enterprise is offered via the parent brand's "Superhuman Go" (writing support plus productivity agents). Prices are in USD and subject to change; check the official site for the latest (as of August 2026).
How it differs from other writing AIs
Grammarly stands out by letting you proofread and improve English in real time wherever you write, plus plagiarism/AI detection and agents. Compared with paraphrase-centric tools or general conversational AIs, its strength is always-on proofreading and detection. However, it effectively does not support Japanese proofreading.
| Aspect | Grammarly | Wordtune | ChatGPT |
|---|---|---|---|
| Focus | Always-on English proofreading/improvement | English rewording | General conversational AI |
| Strength | Grammar/detection, always-on everywhere | Paraphrase, tone | Broad generation |
| Japanese | Effectively unsupported | Effectively unsupported | Supported |
Wordtune, strong at English rewording, and ChatGPT, a general AI, make good points of comparison (for Japanese, DeepL and the like are better suited). If you want to refine English while it is continuously checked, Grammarly is a strong option.
The information on this page is based on the official site as of August 2026. Please check the official site for the latest specifications and pricing.
