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Overview

Grammarly is an AI writing assistant that checks grammar, spelling, style, and tone in real time and proposes improvements. Since 2009 it has been synonymous with English writing assistance, and as of 2026 it runs inside browser extensions, desktop apps, Microsoft Word, Google Docs, Gmail, Slack, and more. The generative side sits under Superhuman Go — the agent layer its parent company Superhuman embeds across any app or browser tab — leaving Grammarly as the writing surface for drafting, rewriting, tone shifting, and translation. The parent company is called Superhuman; the product is still Grammarly. Primary audience: anyone writing English for business, students, and non-native writers.

Key Features

1. Real-Time Grammar & Spell Checking

Grammarly's core strength: instant underlines and fixes for grammar, spelling, and punctuation as you type.

2. AI Assistant (Generative AI)

Prompt-driven text generation, rewriting, summarizing, and tone shifting (formal, casual, confident, etc.). 100 AI prompts/month on Free, 2,000 on Pro, unlimited on Enterprise. Superhuman Go agents also connect to outside services such as Jira, Gmail, Google Drive, and Google Calendar, so they can pull context, file tickets, or check availability without leaving the document you are writing in.

3. Tone Detection & Brand Tone

Automatically detects how your writing reads (formal, friendly, confident, etc.). Team plans let you define a shared brand voice once and have it applied consistently across everyone's writing.

4. Plagiarism and AI-Text Detection (Pro and above)

Compares text against 16 billion+ web pages and academic databases to flag copied content or missing citations. Technology from GPTZero, acquired in June 2026, brings AI-generated-text detection into Pro as a standard feature. Useful for academic work and public content.

5. Works Everywhere You Write

Chrome, Safari, and Edge extensions, Windows/Mac desktop apps, iOS/Android keyboards, and Microsoft Office integration—Grammarly shows up wherever you type.

6. Language Coverage

Basic spelling, grammar, clarity, and tone underlines work across 23+ languages, but the advanced suggestions — including paragraph-level rewrites — are limited to English, Spanish, French, German, Portuguese, and Italian. Translation covers 19 languages including Japanese, handling up to 4,000 characters at a time inside Grammarly itself.

Plans & Pricing (2026)

PlanMonthlyHighlights
Free$0Core grammar/spell checking, tone insights, 100 AI prompts/month
Pro$12 (annual) or $30 (monthly)Full-sentence rewrites, tone tuning, translation, plagiarism + AI detection, 2,000 AI prompts/month
Superhuman Suite Business$33/member (annual) or $40 (monthly)Grammarly bundled with Superhuman Mail, Superhuman Docs, and Superhuman Go
EnterpriseCustomUnlimited AI, BYOK encryption, DLP, custom roles and permissions, cost-center visibility, dedicated support

The standalone Grammarly Business plan is gone; team buyers now land on the Superhuman Suite Business tier, which bundles mail, docs, and agents alongside the writing assistant. Quarterly billing at $60 ($20/month) remains an option.

Typical Use Cases

  • Polishing English business emails and proposals
  • Grammar checking and plagiarism review for academic papers
  • Tone optimization for marketing copy
  • Supporting non-native writers drafting English documents
  • Raising baseline writing quality across a team

Strengths

  • Industry-leading English proofreading accuracy
  • Works everywhere from browsers to Microsoft Office
  • Free plan is genuinely useful
  • Intuitive tone detection and adjustment
  • Makes non-native writing noticeably more persuasive

Weaknesses

  • Japanese is supported for translation only — there is no grammar or style checking for Japanese text
  • Generative features trail dedicated tools like ChatGPT
  • For teams the effective floor is the $33/member/month Superhuman Suite, which is steep if you only want proofreading
  • Monthly price is higher than competing proofreaders
  • Free plan AI prompt quota is tight

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