StealthHumanizer

# 🥷 StealthHumanizer v2 **A comprehensive free & open-source AI text humanizer.** [](https://rudra496.github.io/StealthHumanizer/) [](https://vercel.com/new/clone?repository-url=https://github.com/rudra496/StealthHumanizer) [](LICENSE) [](CONTRIBUTING.md) [](https://github.com/rudra496/StealthHumanizer/stargazers) [](https://github.com/rudra496/StealthHumanizer/network/members) [](https://github.com/rudra496/StealthHumanizer/issues) Transform AI-generated text into **natural, human-like writing** using 13 AI providers, 4 rewrite levels, 13 tones, multi-pass humanization, and a 12-metric detection engine. **✅ 100% Free • No Login • No Limits • Open Source (MIT) • Private & Secure**

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📺 Demo

💡 Try it now: Live Demo on GitHub Pages — no installation needed!

How It Works

📝 AI Text → 🥷 Multi-Pass Rewrite → 📊 AI Detection → 🔁 Re-Humanize → ✅ Human Score 100%

1. Paste your AI-generated text (up to 10,000 words)
2. Select rewrite level, style, and tone
3. Set target human score (50%–100%)
4. Humanize — AI rewrites with human patterns
5. Auto-loop — re-humanizes flagged sentences until target reached
6. Export — copy, download TXT/DOCX

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✨ Features

🥷 Rewrite Engine

Feature	Details
4 Rewrite Levels	Light, Medium, Aggressive, Ninja (5-pass auto-loop)
5 Writing Styles	Academic, Professional, Casual, Creative, Technical
13 Tone Presets	Conversational, Academic Formal/Casual, Journalistic, Creative Writing, Professional, Technical, Persuasive, Storytelling, Humorous, Emotional, Analytical
Multi-Pass Humanization	Ninja: 5 passes, Aggressive: 3 passes, auto-target 100%
Target Score Control	Slider from 50% to 100% human
Alternative Rewrites	Click any sentence for 3 different versions
Side-by-Side Comparison	Diff view with per-sentence scores
16 Languages	Auto-detects and preserves input language

🔍 12-Metric AI Detector

Metric	What It Measures
Perplexity	How predictable/unexpected the word choices are
Burstiness	Sentence length variation (humans vary wildly)
Vocabulary Diversity	Unique word usage vs repetition
Sentence Variation	Length, structure, type diversity
Sentence Start Diversity	Do sentences start the same way?
Pronoun Usage	First/second person pronouns (human indicator)
Transition Frequency	Overuse of formal transitions
Passive Voice	Ratio of passive constructions
AI Phrase Density	Detection of 50+ known AI phrases
Hedging Language	"It could be argued", "one might consider"
Quantifier Patterns	Overuse of "numerous", "various", "multiple"
Contraction Usage	Humans use contractions; AI often doesn't

Readability Scores: Flesch Reading Ease, Flesch-Kincaid Grade Level, Coleman-Liau Index

🆓 13 AI Providers (10 Free!)

Provider	Free?	Speed	Quality	Model
Google Gemini	✅	⚡	⭐⭐⭐⭐⭐	gemini-1.5-flash/pro
Groq	✅	⚡⚡⚡	⭐⭐⭐⭐	llama-3.3-70b
ZAI (GLM-5)	✅	⚡⚡	⭐⭐⭐⭐⭐	glm-5
OpenRouter	✅	⚡⚡	⭐⭐⭐⭐	100+ models
Together AI	✅	⚡⚡	⭐⭐⭐⭐	llama-3-70b
Cerebras	✅	⚡⚡⚡	⭐⭐⭐⭐	llama3.1-70b
Mistral AI	✅	⚡⚡	⭐⭐⭐⭐	mistral-large
Cohere	✅	⚡⚡	⭐⭐⭐	command-r-plus
DeepInfra	✅	⚡⚡	⭐⭐⭐⭐	llama-3-70b
HuggingFace	✅	⚡	⭐⭐⭐	llama-3-8b
Cloudflare Workers AI	✅	⚡⚡⚡	⭐⭐⭐	llama-3-8b
OpenAI GPT-4	❌	⚡	⭐⭐⭐⭐⭐	gpt-4o
Anthropic Claude	❌	⚡	⭐⭐⭐⭐⭐	claude-sonnet-4

💡 No API key? Start with Gemini or Groq — both free, no credit card needed!

🎨 UX Features

• 🌙 Dark / ☀️ Light mode
• ⌨️ Keyboard shortcuts (Ctrl+Enter, Ctrl+1/2/3/4)
• 📜 History (localStorage, 50 entries)
• 📋 Copy / 💾 Export as TXT & DOCX
• 📱 Fully mobile responsive
• 🔒 Zero server data storage
• 🏃 No account or sign-up required

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🚀 Quick Start

Option 1: 🌐 Use Online (Zero Install)

👉 Live Demo — add any free API key and start humanizing!

Option 2: 🚀 Deploy on Vercel (Recommended)

Option 3: 💻 Run Locally

git clone https://github.com/rudra496/StealthHumanizer.git
cd StealthHumanizer
npm install
npm run dev

Step-by-Step Usage

1. Get a free API key:

   • Google Gemini — Sign in → Create API Key → Copy
   • Groq — Sign up → Create key → Paste

2. Paste your AI-generated text

3. Configure:

   • Level: Light / Medium / Aggressive / Ninja
   • Style: Academic / Professional / Casual / Creative / Technical
   • Tone: Conversational / Formal / Journalistic / etc.
   • Target: 80% → 100%

4. Click "Humanize" — get human-like natural writing!

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🏆 StealthHumanizer vs Others

Feature	StealthWriter	QuillBot	StealthHumanizer
Price	$20–50/mo	$19.95/mo	FREE forever
Daily Limit	10–150	Limited	Unlimited
Word Limit	1K–5K	1.2K	10K
AI Providers	1	1	13 (10 free)
Rewrite Levels	3	2	4 (+ Ninja)
Writing Styles	3	4	5
Tone Presets	0	0	13
Multi-Pass	❌	❌	✅ (up to 5)
Target Score	❌	❌	✅ (50–100%)
AI Detector	Basic	None	12 metrics
Readability	❌	❌	3 scores
Open Source	❌	❌	✅ MIT
Self-Hostable	❌	❌	✅
API Keys Stored	Their server	Their server	Your browser only
No Account	❌	❌	✅

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🛠️ Tech Stack

Layer	Technology
Framework	Next.js 14 (App Router)
Language	TypeScript
Styling	Tailwind CSS
AI Integration	Native fetch() — zero SDK dependencies
Deployment	Vercel / GitHub Pages
Dependencies	next, react, lucide-react — that's it

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🔒 Security & Privacy

• 🔑 API keys never leave your browser — stored only in localStorage
• 🚫 No server-side storage — no databases, no user accounts
• 🔐 All API calls use HTTPS — encrypted in transit
• 📵 No tracking, no analytics — zero third-party scripts
• 🛡️ MIT Licensed — fully transparent, auditable code
• See SECURITY.md for full security policy

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📁 Project Structure

StealthHumanizer/
├── app/
│   ├── api/
│   │   ├── humanize/route.ts    # Multi-pass humanization endpoint
│   │   └── alternative/route.ts # Alternative rewrite suggestions
│   ├── layout.tsx               # Root layout with metadata
│   ├── page.tsx                 # Main application page
│   └── globals.css              # Global styles + dark mode
├── components/
│   ├── Humanizer.tsx            # Main humanization interface
│   ├── Detector.tsx             # AI detection dashboard
│   ├── Settings.tsx             # API key management
│   ├── History.tsx              # Humanization history
│   ├── Navbar.tsx               # Navigation bar
│   └── Toast.tsx                # Notification toasts
├── lib/
│   ├── types.ts                 # TypeScript types
│   ├── providers.ts             # 13 AI provider configs
│   ├── prompts.ts               # 13 tones × 4 levels system prompts
│   ├── detector.ts              # 12-metric AI detection engine
│   ├── humanizer.ts             # Multi-pass humanization logic
│   ├── readability.ts           # Readability score calculations
│   └── storage.ts               # localStorage management
├── docs/
│   ├── index.html               # Standalone GitHub Pages version
│   ├── sitemap.xml              # SEO sitemap
│   └── robots.txt               # Crawler rules
├── .github/
│   ├── workflows/
│   │   ├── pages.yml            # GitHub Pages auto-deploy
│   │   └── ci.yml               # Build verification
│   └── ISSUE_TEMPLATE/          # Bug report & feature request
└── [Documentation files]
    ├── README.md                ← You are here
    ├── ARCHITECTURE.md          # System architecture
    ├── STYLE_ENGINE.md          # Tone/style system design
    ├── API_USAGE.md             # Provider API details
    ├── SECURITY.md              # Security policy
    ├── CONTRIBUTING.md          # How to contribute
    ├── ROADMAP.md               # Future plans
    ├── CODE_OF_CONDUCT.md       # Community guidelines
    └── LICENSE                  # MIT License

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🗺️ Roadmap

• [x] v1: Core humanization engine
• [x] v2: 13 providers, 13 tones, multi-pass, ninja mode
• [x] GitHub Pages deployment
• [x] SEO optimization & structured data
• [x] GitHub Actions CI/CD
• [ ] v3: Browser extension (Chrome/Firefox)
• [ ] v3: Real-time streaming humanization
• [ ] v3: Batch processing (multiple texts)
• [ ] v3: Custom model fine-tuning guide

See ROADMAP.md for full details.

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🤝 Contributing

Contributions are welcome! Please read CONTRIBUTING.md first.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/amazing)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing)
5. Open a Pull Request

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📄 License

This project is licensed under the MIT License — use it however you want.

See LICENSE for details.

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**Built with ❤️ by [Rudra Sarker](https://github.com/rudra496)** [](https://twitter.com/Rudra496) [](https://rudra496.github.io/site) [](https://github.com/rudra496)

_{Shahjalal University of Science and Technology, Bangladesh}

**⭐ If you find this useful, please give it a star! It helps more than you know.**

Built With

• css
• javascript
• typescript