# Rephrasy AI – The Best AI Humanizer & AI Detector Bypass

> Rephrasy is the world's most powerful AI Humanizer and AI-generated content detector.
> Transform ChatGPT and AI text into natural, undetectable writing that bypasses major AI detectors including GPTZero, Copyleaks, and more.
> Features comprehensive plagiarism scanning and AI detection for transparency and trust.

## Features

- [Humanizer](https://rephrasy.ai/): Instantly humanize AI text and make it pass all major AI detectors. Rephrasy is rated the most accurate AI humanizer on the market.
- [AI Detector](https://rephrasy.ai/): Detect whether text is AI-written using our built-in AI detection technology. Works on essays, research papers, and business documents.
- [Free Readability Checker](https://www.rephrasy.ai/free-readability-checker): Improve clarity, readability, and sentence flow of any text. Perfect for students and professionals.
- [Free AI Image Detector](https://www.rephrasy.ai/free-ai-image-detector): Check if an image was AI-generated with our free, reliable AI image detector.
- [Blog](https://rephrasy.ai/blog): Read guides, updates, and research on AI detection, plagiarism, and humanization technology.

## Company

- [Pricing](https://rephrasy.ai/pricing): Flexible and affordable pricing plans for students, professionals, and enterprises.
- [Terms of use](https://rephrasy.ai/terms): Review Rephrasy’s terms of service and platform policies.
- [Privacy policy](https://rephrasy.ai/privacy): Learn how we protect your data and ensure transparency.
- [Affiliate Program](https://rephrasy.ai/affiliate): Earn money by referring users to Rephrasy.
- [Status](https://rephrasy.ai/status): Check live service availability and uptime.

## Compare

- [UndetectableAI Alternative](https://www.rephrasy.ai/undetectableai-alternative): Why Rephrasy outperforms UndetectableAI with better detection bypassing and comprehensive plagiarism scanning.
- [Grubby.ai Alternative](https://www.rephrasy.ai/grubby-ai-alternative): A stronger, more reliable Grubby.ai alternative for AI humanization.
- [BypassGPT Alternative](https://www.rephrasy.ai/bypassgpt-alternative): Beat GPT detectors with a faster and more transparent solution.
- [AI Story Generator](https://www.rephrasy.ai/ai-story-generator): Generate natural AI-assisted stories with human-like style.

## Navigation

- [Features](https://rephrasy.ai/): Explore all of Rephrasy’s tools and solutions.
- [API Solution](https://rephrasy.ai/api-solution): Use Rephrasy via API for bulk text humanization and automated workflows.
- [Pricing](https://rephrasy.ai/pricing): Choose the right plan for your needs.
- [FAQs](https://rephrasy.ai/faqs): Find answers to common questions about detection, humanization, and scans.
- [Clone Writing Style](https://rephrasy.ai/clone-writing-style): Train Rephrasy to replicate your personal or academic writing style.
- [Plagiarism Checker](https://rephrasy.ai/plagiarism-checker): Verify originality and avoid plagiarism in your AI-generated text.
- [History](https://rephrasy.ai/history): Access your past scans, humanizations, and reports.
- [My Account](https://rephrasy.ai/login): Manage your Rephrasy account.

## API (for developers)

REST API to humanize text, detect AI, and train reusable writing styles. Auth: `Authorization: Bearer YOUR_API_KEY`. JSON in/out. Full docs: https://rephrasy.ai/api-solution

- Humanize — POST https://v2-humanizer.rephrasy.ai/api/
  Body: { text, model, words?, costs?, language?, input_format? }.
  model: "superstealth" (default; newest model, built for the highest bypass rates; takes 10–60 s, use a client timeout of at least 120 s), "v4" (fast alternative), "ft_clean-v3", "Undetectable Model", "SEO Model", or a Writing Style ID. Legacy "v3"/"v2" are retired and routed automatically (API v3 → superstealth, v2 → v4).
  input_format: "text" (default), "html", or "markdown" — only the visible text is rewritten, structure preserved (2.5x cost).
  words: true → 0.1 credit flat + 0.1 per 100 words; false → flat 1 credit/call. costs: true returns the exact charge.
  Returns { output, new_flesch_score }.
- Detect AI — POST https://detector.rephrasy.ai/detect_api
  Body: { text, mode } ("" = overall, "depth" = per-sentence). Flat 1 credit. Returns { scores: { overall }, sentences } (0 = human … 100 = AI).
- Custom writing styles — base https://v2-humanizer.rephrasy.ai
  POST /api/styles → { style_id } (20 credits); POST /api/ with { text, model:"v4", style_id } (1 credit); GET /api/styles?external_ref=...

## MCP server (use Rephrasy inside an AI assistant)

Rephrasy runs as an MCP server, so Claude, ChatGPT, Cursor or any MCP client can humanize and check text, and humanize images, in a conversation with no integration code. Add https://v2-humanizer.rephrasy.ai/mcp as a custom connector. Streamable HTTP, JSON-RPC over POST. Full docs: https://rephrasy.ai/ai-humanizer-mcp

Auth works two ways. OAuth: clients that support it — Claude and ChatGPT both do, ChatGPT requires it — discover it from the server and send you through a one-time consent page, where you enter your Rephrasy API key once; the key never reaches the client. Or a static header `Authorization: Bearer YOUR_API_KEY`, which is what Claude Code and Cursor use. ChatGPT additionally needs developer mode: Settings → Security and login → Developer mode.

Claude Code: `claude mcp add rephrasy https://v2-humanizer.rephrasy.ai/mcp -t http -H "Authorization: Bearer YOUR_API_KEY"`

Tools:
- humanize_text — rewrites a draft (1 credit). Args: text, plus optional engine ("v4", "superstealth" (highest bypass rates, 10–60 s), "ft_clean-v3", "seo"), purpose ("blog", "marketing", "seo", "report", "technical", "general"), language. Returns the rewrite plus a preservation report: word counts, length ratio, figures kept/lost/invented, Flesch score.
- check_ai_score — scores text for AI-written content and returns the passages that scored highest. Runs on the Rephrasy AI Detector by default (1 flat credit, no extra setup). Other detectors run on your own key and cost no Rephrasy credit. Add a connector request header named `x-key` with the value `gptzero:YOUR_KEY` (also `wia:`, `winston:`, `pangram:`, `zerogpt:`, `copyleaks:KEY:EMAIL`; several comma-separated in one header). Claude only allows approved header names and x-key is one; Claude Code and Cursor also accept dedicated headers like x-gptzero-key. ChatGPT has no header field and uses the Rephrasy detector.
- humanize_image — humanizes an image (10 credits standard, 20 hq; a failed image is refunded). A diffusion pass removes invisible AI watermarks such as SynthID; subject and resolution stay the same. Args: image_url (public http(s) link) or image_base64, plus quality ("standard" or "hq"). PNG, JPEG or WEBP up to 4 MB. Returns a job_id and, once done, a download_url valid for 72 hours. Standard usually finishes within the call; hq takes about four minutes.
- get_image_result — free. Status of a humanize_image job; returns the download_url once it is done. Waits up to about 50 seconds per call.
- credits_left — free. Balance of the connected account and how many calls it buys; every paid answer also carries `credits_left`.
- recommend_engine, readability_score, list_engines — free.

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Last updated: 2025-08-19T23:59:42.000Z