I Built StealthHumanizer — A Free, Open-Source AI Text Humanizer (13 Providers, No Login)

The Problem

AI detectors like GPTZero, Turnitin, and Originality.ai are everywhere. Students, writers, and professionals are getting flagged even when they write their own content. And the paid "humanizers" charge $10-20/month for something that should be free.

What I Built

StealthHumanizer is a completely free, open-source AI text humanizer that runs in your browser. No login. No limits. No server-side data storage.

Try it live: stealthhumanizer.vercel.app

Features

• 13 AI Providers — Gemini (free), OpenAI, Claude, Groq (free), Mistral, Cohere, Together, OpenRouter, Cerebras, DeepInfra, HuggingFace, Cloudflare, ZAI
• 4 Rewrite Levels — Light, Medium, Aggressive, Ninja (multi-pass auto-refinement)
• 6 Writing Styles — Academic, Professional, Casual, Creative, Technical, Humanize
• 13 Tone Presets — Conversational, Journalistic, Persuasive, Storytelling, and more
• Built-in AI Detection Scoring — 12-metric analysis with confidence intervals
• File Upload — PDF, DOCX support
• 16+ Languages — English, Chinese, Spanish, French, German, Japanese, Korean, Arabic, Hindi...
• Batch Processing — Humanize multiple texts at once
• 100% Private — API keys stored browser-side only

How It Works

It uses a 4-layer humanization pipeline:

1. LLM Rewrite — Your chosen AI provider rewrites the text using anti-detection prompts
2. Non-LLM Post-Processing — 500+ synonym swaps, 230+ collocation replacements, AI vocabulary removal
3. Multi-Model Chain (Optional) — Pass text through multiple AI providers to mix statistical fingerprints
4. Final Polish — Light cleanup with readability guards

Quick Start

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

Comparison

Links

• GitHub: github.com/rudra496/StealthHumanizer
• Live Demo: stealthhumanizer.vercel.app

If this saves you money on paid humanizers, consider giving it a star on GitHub!

Built by Rudra Sarker — MIT License