Swadhinbiswas
OpenGrammar Open-source, self-hostable Grammarly alternative
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What is Swadhinbiswas?
OpenGrammar is a free, open-source browser extension that serves as a privacy-first alternative to Grammarly. It provides grammar, spelling, and tone adjustments for writing everywhere online—including Gmail, Google Docs, Notion, Reddit, and any textarea. The tool runs completely free with zero monthly fees and allows users to self-host the entire infrastructure.
The core engine operates locally in your browser using a dual-engine architecture. The local rules engine checks for passive voice, repeated words, and overly long sentences offline without needing a server. For advanced AI-powered corrections including complex grammar, tone rewriting, and clarity suggestions, users can plug in their own API key from OpenAI, Groq, OpenRouter, Together, or local models via Ollama.
OpenGrammar is designed for writers, developers, and privacy enthusiasts who want Grammarly-like functionality without sending keystrokes to third-party servers or paying subscription fees. It features 8 tone options (formal, casual, professional, etc.), contextual UI with color-coded underlines, and a 156,000-word offline dictionary. The backend is stateless and self-hostable via Cloudflare Workers, Vercel Edge, Docker, NPM, or Netlify.
The tool maintains absolute privacy with no databases, no user accounts, and no telemetry. Your API key never leaves your browser storage, and text processed through AI is immediately deleted via stateless edge functions. Everything is open source under Apache 2.0 license.
Swadhinbiswas pricing
Pricing model: Freemium
Completely free with zero monthly fees. The core local rules engine runs 100% offline at no cost. For AI-powered advanced features, users bring their own API key from OpenAI, Groq, OpenRouter, Together, or use local models via Ollama. Users pay only fractions of a cent per month directly to their chosen API provider instead of a $12-30/month Grammarly subscription. No paid tiers, no premium plans, no usage caps. The backend can be self-hosted free on Cloudflare Workers or Vercel Edge with their free tiers.
Swadhinbiswas pros
- Completely free with zero monthly subscription fees
- Open-source under Apache 2.0 license
- Runs locally offline for basic grammar checks
- 156,000-word offline dictionary included
- No user accounts or databases required
- No telemetry or data tracking
- Self-hostable backend via one command
- Bring your own AI API key (OpenAI, Groq, OpenRouter, Together, Ollama)
- Works everywhere: Gmail, Google Docs, Notion, Reddit, any textarea
- 8 tone rewriting options via right-click or shortcut
- Color-coded contextual UI (red, yellow, blue underlines)
- API key never leaves your browser storage
- AI-processed text immediately deleted via stateless edge functions
- Pay fractions of a cent per month instead of $12-30/month
- Passive voice and repetition detection built-in
Swadhinbiswas cons
- Requires manual installation as unpacked Chrome extension
- Advanced AI features require bringing your own API key
- No native mobile app available
- Must enable Developer Mode in Chrome to load
- No official Chrome Web Store listing yet
- Limited to browser-based writing only
- Self-hosting requires technical knowledge
- No customer support or SLA guarantees
Frequently asked questions about Swadhinbiswas
What is OpenGrammar?
OpenGrammar is a free, open-source browser extension and privacy-first writing assistant that serves as a Grammarly alternative. It provides grammar, spelling, and tone adjustments everywhere you write online, with a dual-engine architecture that runs local rule-based checks offline and offers AI-powered corrections when you add your own API key.
Is OpenGrammar really free?
Yes, OpenGrammar is completely free with zero monthly fees. The core engine runs 100% locally in your browser with a 156,000-word offline dictionary, catching misspellings, passive voice, and weak phrasing without any server costs. For AI features, you only pay fractions of a cent directly to your API provider.
How does the dual-engine architecture work?
OpenGrammar uses two engines: (1) A local rules engine that runs offline in your browser, checking for passive voice, repeated words, and overly long sentences with zero dependencies. (2) AI processing for complex grammar, tone rewriting, and clarity suggestions that uses your personal API key sent securely to an LLM via stateless edge functions.
What AI providers does OpenGrammar support?
OpenGrammar supports OpenAI, Groq, OpenRouter, Together AI, and local models via Ollama. You paste in your own API key and pay directly to the provider at fractions of a cent per use instead of a monthly subscription.
Where does OpenGrammar work?
OpenGrammar works everywhere you write online: Gmail, Google Docs, Notion, Reddit, and any textarea on any website. It is a browser extension that provides Grammarly-like writing help in all these locations.
How private is OpenGrammar?
OpenGrammar offers paranoid-level privacy: no databases, no user accounts, no telemetry. Your API key never leaves your browser storage. The local engine runs completely offline. AI requests go to a stateless edge function and are immediately forgotten. You own your data entirely.
How do I install OpenGrammar?
Clone the repository with git clone https://github.com/swadhinbiswas/opengrammar.git, navigate to extension/ and run bun install followed by bun run build. Then go to chrome://extensions, enable Developer Mode, and select the dist/ folder to load the unpacked extension.
Can I self-host OpenGrammar?
Yes, you can self-host the entire backend. Deploy your own Cloudflare Worker or Vercel Edge function in a single command. The backend also supports Docker, NPM, and Netlify. It is stateless with nothing stored, and you own the entire infrastructure.
What tone options are available?
OpenGrammar offers 8 tone rewriting options including formal, casual, and professional. You can rewrite text via right-click context menu or keyboard shortcut to change the tone of yourwriting.
What is the license for OpenGrammar?
OpenGrammar is open source under the Apache 2.0 license. Everything is open source with no accounts required and no telemetry, allowing you to inspect, modify, and distribute the code freely.