# Grammarly vs OpenCat

Grammarly records 58,867,412 monthly visits with -1.5% month-over-month growth and Freemium pricing. OpenCat records 5,083 monthly visits with -8.2% growth and Freemium, Free Trial pricing.

| Metric | [Grammarly](https://openaitools.app/tool/grammarly) | [OpenCat](https://openaitools.app/tool/opencat) |
| :--- | :--- | :--- |
| Website URL | https://www.grammarly.com | https://opencat.app |
| Categories | AI Writing Assistants, AI Writing, AI Grammar Checker, AI Text Generator | AI Chatbot, AI Assistant, Text to Image, AI Translate |
| Pricing Model | Freemium | Freemium, Free Trial |
| Monthly Visits | 58,867,412 | 5,083 |
| MoM Growth Rate | -1.5% | -8.2% |
| Primary Market | United States | United States |
| Direct Visits | 25,398,749 | 2,034 |
| Review Score | 4.4 | 4.6 |
| Saved Count | 74 | 5 |
| Supported Platforms | Website | Website |

## Grammarly

Grammarly is the world's most widely deployed AI writing and communication platform, trusted by more than 40 million daily users and 50,000 organizations including Atlassian, Databricks, and Zoom. Operating as a persistent overlay across over 500,000 web applications, desktop programs (Windows and macOS), Microsoft Office, Google Docs, and iOS/Android keyboards, Grammarly analyzes text in real time to eliminate grammatical errors, streamline wordy phrasing, and calibrate tone to match the writer's intent. Following its corporate evolution under the Superhuman Platform umbrella alongside Superhuman Mail and Coda, Grammarly has expanded from a personal proofreader into an enterprise-grade proactive AI communication suite.

In 2026, Grammarly goes well beyond red-underline spellchecking with a suite of specialized AI Agents and document integrity tools. Writers can invoke purpose-built agents—including AI Grader, Citation Finder, Reader Reactions, and Paraphraser—alongside generative AI drafting directly inline where they work. To address academic and professional transparency in the generative AI era, Grammarly offers built-in Plagiarism Detection, an AI Detector, and Grammarly Authorship, which tracks how a document was constructed by automatically categorizing text as human-typed, pasted from external sources, or generated/modified with AI. For teams, Grammarly enforces organizational consistency through custom Style Guides, Brand Tones, reusable Snippets, and Knowledge Share.

Grammarly simplified its subscription structure by consolidating its legacy individual 'Premium' and team 'Business' offerings into a single unified tier: Grammarly Pro. The Free plan ($0/month) covers essential spelling, punctuation, basic tone visibility, and 100 generative AI prompts per month. Grammarly Pro is priced at $12/member/month when billed annually ($144/year) or $30/member/month when billed monthly ($60 quarterly), unlocking unlimited personalized fluency suggestions, full-sentence rewrites, tone adjustment, citation formatting, plagiarism and AI detection, 1 team style guide, and 2,000 generative AI prompts per member each month. Large organizations opt for Grammarly Enterprise (available with Superhuman Go) for unlimited AI prompts, SAML SSO, SCIM provisioning, Data Loss Prevention (DLP), and Bring Your Own Key (BYOK) encryption.

**Pricing & Plans:** Free plan ($0/month) includes core grammar and spelling checks, tone detection, and 100 generative AI prompts/month; Grammarly Pro costs $12/member/month billed annually ($144/year, or $30/month billed monthly) with full-sentence rewrites, plagiarism/AI detection, team style guides, and 2,000 AI prompts/month, while Enterprise offers custom pricing with unlimited AI prompts and BYOK security.

- **Ubiquitous Inline Rewriting & Tone Calibration:** Works natively inside Chrome, Safari, Firefox, Edge, Windows, Mac, Google Docs, MS Office, and mobile keyboards to flag grammar mistakes, rewrite tangled sentences, and shift tone toward confident, empathetic, or executive registers.
- **Specialized AI Agents (AI Grader, Citation Finder & Reader Reactions):** Deploys contextual AI agents that predict how a target audience will react to a draft, locate credible supporting citations, grade essays against rubric criteria, and generate drafts using up to 2,000 monthly prompts on Pro.
- **Grammarly Authorship, AI Detector & Plagiarism Checker:** Scans text against billions of web pages and academic databases for accidental plagiarism, detects AI-generated passages, and logs transparent document provenance via Authorship reports in Google Docs and Word.
- **Team Style Guides, Brand Tones & Knowledge Share:** Enables teams on Pro and Enterprise plans to codify company terminology, ban deprecated jargon, enforce inclusive language, insert shared Snippets, and surface internal company definitions inline.
- **Enterprise Security, DLP & Superhuman Platform Governance:** Protects organizational data with SOC 2 Type 2 attestation, SAML SSO, SCIM lifecycle management, Confidential Mode, Data Loss Prevention controls, Audit Logs API, and customer-managed BYOK encryption.

**Strengths:** Frictionless cross-platform integration works inside virtually every browser, desktop app, email client, and mobile OS without copy-pasting into a separate chatbot.; Consolidating Premium and Business into Grammarly Pro ($12/member/month annual) gives individuals and small teams access to style guides, analytics, and plagiarism/AI detection in one plan.; Grammarly Authorship provides a constructive, transparent audit trail for students and writers to demonstrate human writing integrity alongside responsible AI editing.; Mature enterprise security posture featuring BYOK encryption, Data Loss Prevention, and granular application/domain blocklists.

**Limitations:** Month-to-month billing on Grammarly Pro is steep at $30/member/month compared to the $12/member/month annual commitment ($144 billed upfront).; Core writing intelligence and style rules remain primarily optimized for English dialects (US, UK, Canadian, Australian, Indian) rather than native multilingual grammar checking.; Aggressive inline underlines and pop-up agent cards can feel visually intrusive in dense technical documents or code-heavy web editors unless muted per domain.

[Profile (Markdown)](https://openaitools.app/tool/grammarly.md)

## OpenCat

OpenCat is a native AI client for Apple platforms, designed so that chatting with an AI assistant feels as smooth as using any well-made Mac or iOS app. Instead of relying on a web interface, it ships as a downloadable application for macOS and a mobile app for iPhone and iPad, with fast, responsive scrolling, native text selection, and system-level integrations that a browser tab simply cannot offer.

Its feature set reaches well beyond a plain chat window. OpenCat supports multiple AI models, so you can route different tasks to different assistants, and includes a prompt library to save the prompts you use repeatedly. Voice chat lets you hold a spoken conversation and hear replies, while Siri Shortcuts let you jump into a chat without opening the app. The keyboard extension is the standout: it puts AI completion and question answering directly into Messages, Notes, Mail, and other apps. On top of that, OpenCat handles text-to-image generation, image-based conversations, translation, and Markdown rendering with bold, italics, links, and code blocks.

Pricing is structured to meet different needs. The free tier covers the essentials — prompt library, Markdown rendering, and access to multiple models — while the one-time OpenCat Pro purchase unlocks the keyboard extension, iCloud sync, Siri integration, and text to speech. A separate Cloud AI subscription provides fast access to multiple hosted models, including voice chat, vision chat, and text to image, for people who would rather not manage their own API keys. The app is built by an independent developer and is not affiliated with OpenAI, Anthropic, or any other model vendor it can connect to.

**Pricing & Plans:** OpenCat uses a freemium model: a free tier plus a one-time OpenCat Pro purchase (about $9.99) and an optional Cloud AI subscription (about $2.99 monthly or $19.99 annually), with a 3-day free trial on cloud plans.

- **AI in every app via keyboard extension:** The keyboard extension brings AI text generation into Messages, Notes, Mail, and any other app on your device, so you never have to switch contexts to ask a question.
- **Voice chat and Siri integration:** Talk to your assistant hands-free and hear spoken replies, with Siri Shortcuts for triggering a chat without opening the app.
- **Multiple models and prompt library:** Switch between different AI models and providers for different tasks, and keep a curated prompt library ready for recurring needs.
- **Image generation, vision chat, and translation:** Generate images from text prompts, discuss photos inside a conversation, and translate text between languages without leaving the chat.
- **Markdown rendering and iCloud sync:** Format answers with bold, italics, links, and code, and sync conversations and settings through iCloud across your Apple devices.

**Strengths:** Native macOS and iOS apps with fluid, responsive performance; Keyboard extension lets you use AI in any app without switching windows; Choice of built-in cloud models or bringing your own API key; One-time Pro purchase option instead of a mandatory subscription

**Limitations:** Some of the best features, like the keyboard extension and Siri integration, require the Pro purchase; Heavy cloud usage depends on a separate subscription or your own API keys and provider limits; Closest competitors offer broader team and enterprise administration features

[Profile (Markdown)](https://openaitools.app/tool/opencat.md)

## Frequently Asked Questions

### How do Grammarly and OpenCat compare in monthly traffic?

Grammarly has 58,867,412 monthly visits, while OpenCat has 5,083. Traffic estimates describe audience size, not product quality.

### How do their growth rates compare?

Grammarly has a month-over-month growth rate of -1.5%; OpenCat has -8.2%.

### How does pricing compare?

Grammarly: Freemium. Free plan ($0/month) includes core grammar and spelling checks, tone detection, and 100 generative AI prompts/month; Grammarly Pro costs $12/member/month billed annually ($144/year, or $30/month billed monthly) with full-sentence rewrites, plagiarism/AI detection, team style guides, and 2,000 AI prompts/month, while Enterprise offers custom pricing with unlimited AI prompts and BYOK security. OpenCat: Freemium, Free Trial. OpenCat uses a freemium model: a free tier plus a one-time OpenCat Pro purchase (about $9.99) and an optional Cloud AI subscription (about $2.99 monthly or $19.99 annually), with a 3-day free trial on cloud plans.

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [ChatGPT](https://openaitools.app/tool/chatgpt-4) | 6,048,022,723 | +2.2% | Freemium | OpenAI's flagship multimodal assistant powered by GPT-6 and GPT-5.6 for reasoning, coding, and deep research. | [.md](https://openaitools.app/tool/chatgpt-4.md) |
| 2 | [DeepL](https://openaitools.app/tool/deepl) | 95,110,871 | -1.7% | Freemium | Outstanding for context-aware translation and professional writing refinement, but not designed as a dedicated grammar checker. | [.md](https://openaitools.app/tool/deepl.md) |
| 3 | [QuillBot Paraphraser](https://openaitools.app/tool/quillbot-paraphraser) | 36,630,337 | +2.3% | Freemium | Excels at heavy paraphrasing and text rewriting, but offers less seamless inline real-time proofreading across all apps. | [.md](https://openaitools.app/tool/quillbot-paraphraser.md) |
| 4 | [Poe](https://openaitools.app/tool/poe) | 5,894,702 | +9.1% | Freemium | One app to chat with GPT, Claude, Gemini and hundreds of other AI models | [.md](https://openaitools.app/tool/poe.md) |
| 5 | [LanguageTool](https://openaitools.app/tool/languagetool) | 5,707,795 | -4.2% | Freemium | Provides strong multilingual grammar and style checking across apps, but offers fewer advanced generative AI features. | [.md](https://openaitools.app/tool/languagetool.md) |
| 6 | [Monica](https://openaitools.app/tool/monica-ai) | 4,512,775 | -11.3% | Freemium | All-in-one AI assistant across web, browser, desktop and mobile | [.md](https://openaitools.app/tool/monica-ai.md) |
| 7 | [Sider](https://openaitools.app/tool/sider-ai-extension) | 2,644,740 | -10.6% | Freemium | Your AI agent for the browser: chat, automate and create from one sidebar | [.md](https://openaitools.app/tool/sider-ai-extension.md) |
| 8 | [ProWritingAid](https://openaitools.app/tool/prowritingaid-com) | 1,623,266 | +17.6% | Freemium, Paid | Delivers deeper manuscript analysis and structural reports, but has a steeper learning curve than Grammarly. | [.md](https://openaitools.app/tool/prowritingaid-com.md) |
| 9 | [Merlin AI](https://openaitools.app/tool/merlin-ai) | 1,382,634 | +13.1% | Freemium | One-click AI assistant for browsing, writing and research | [.md](https://openaitools.app/tool/merlin-ai.md) |
| 10 | [Paperpal](https://openaitools.app/tool/paperpal) | 1,111,641 | +1.7% | Freemium | AI academic writing assistant that edits, cites, and checks your manuscript right where you write | [.md](https://openaitools.app/tool/paperpal.md) |

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Source: https://openaitools.app/compare/grammarly-vs-opencat

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