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

#writing

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:

LLM Rewrite — Your chosen AI provider rewrites the text using anti-detection prompts
Non-LLM Post-Processing — 500+ synonym swaps, 230+ collocation replacements, AI vocabulary removal
Multi-Model Chain (Optional) — Pass text through multiple AI providers to mix statistical fingerprints
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

	StealthHumanizer	QuillBot	StealthWriter	Undetectable.ai
Price	Free	$9.99/mo	$19/mo	$14.99/mo
Open Source	Yes	No	No	No
Providers	13	1	1	1
No Login	Yes	No	No	No
Self-Hostable	Yes	No	No	No

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