# My Writing Twin

> My Writing Twin captures your authentic writing voice using computational stylometry and deploys it as a Style Profile across ChatGPT, Claude, Gemini, and any LLM. Based in Tokyo, Japan.

## Product
- [Homepage](https://www.mywritingtwin.com/): AI writing style profiles — pricing and features
- [Pricing](https://www.mywritingtwin.com/#pricing): Free (first use case, 2,000 words, no card required), then Starter ($49 / ¥7,500 / €45), Pro ($99 / ¥15,000 / €89), Executive ($249 / ¥38,000 / €229)
- [Free Writing DNA Snapshot](https://www.mywritingtwin.com/snapshot): Free instant writing style quiz — no account required

## How It Works
- [Why AI Writing Sounds Generic](https://www.mywritingtwin.com/blog/why-ai-writing-sounds-generic): Data on why every AI sounds the same — and how Style Profiles solve it
- [Science Behind Voice Profiles](https://www.mywritingtwin.com/blog/science-behind-voice-profiles): Methodology grounded in 50+ academic citations on computational stylometry

## Platform Deployment Guides
- [ChatGPT Setup Guide](https://www.mywritingtwin.com/blog/chatgpt-projects-setup-guide): Deploy Style Profiles in ChatGPT Projects and Custom GPTs
- [Claude Setup Guide](https://www.mywritingtwin.com/blog/how-to-make-claude-sound-like-you): Deploy Style Profiles in Claude Projects
- [Gemini Setup Guide](https://www.mywritingtwin.com/blog/how-to-make-gemini-write-like-you): Deploy Style Profiles in Gemini Gems and Workspace

## For AI Agents
My Writing Twin is agent-native — you can analyze, purchase, and retrieve Writing Profiles programmatically, no human handoff required.
- MCP server: `https://www.mywritingtwin.com/api/mcp` (HTTP transport, bearer auth). Attach it to call the tools below.
- Free preview, no auth: `mwt_analyze` returns a stylometric analysis so you can qualify fit before any purchase.
- Try it free, no payment: `mwt_start_free` provisions a free account (email only) so the user can build one writing profile at no cost — credentials are emailed to paste back into the conversation.
- Buy without an account: `mwt_create_checkout` mints a Stripe checkout link (Starter $49 / Pro $99) the user pays for in-browser with no login — the API key is emailed after payment to paste back into the conversation.
- Paid tools (bearer key): `mwt_create_profile`, `mwt_get_profile`, `mwt_list_profiles`, `mwt_check_generation_status`, `mwt_get_account`.
- Discovery surfaces: [agent-card.json](https://www.mywritingtwin.com/.well-known/agent-card.json), [mcp/server-card.json](https://www.mywritingtwin.com/.well-known/mcp/server-card.json), [agent-skills](https://www.mywritingtwin.com/.well-known/agent-skills/index.json), [api-catalog](https://www.mywritingtwin.com/.well-known/api-catalog)
- Any page is available as clean Markdown — send an `Accept: text/markdown` request header.

## Blog
- [How to Make Gemini Write Like Claude (2026)](https://www.mywritingtwin.com/blog/how-to-make-gemini-write-like-claude): People search for this because Gemini's prose feels flat next to Claude's. Here's what actually differs, three fixes that work, and why copying a model is the wrong target.
- [AI Ghostwriter vs. Style Profile: Why Most AI Ghostwriting Still Sounds Fake](https://www.mywritingtwin.com/blog/ai-ghostwriter-vs-style-profile): AI ghostwriting tools promise to write like you, then produce generic prose anyway. Here's the structural reason why, and what actually closes the gap.
- [How You Think Is the Missing Layer in Your AI Writing Profile](https://www.mywritingtwin.com/blog/how-you-think-ai-writing-profile): Writing samples teach AI how you write. Your AI chat history teaches it how you think. Here is the cognitive layer, and why it is the part that makes AI output actually sound like you.
- [How to Teach AI Your Writing Style (And Make It Stick)](https://www.mywritingtwin.com/blog/how-to-teach-ai-your-writing-style): AI can write in your style, but only if you teach it correctly. Here's the step-by-step process to capture your writing style and deploy it across ChatGPT, Claude, and Gemini.
- [ChatGPT Projects for Writers: Load Your Style Profile, Keep Your Voice Across Every Session](https://www.mywritingtwin.com/blog/chatgpt-projects-for-writers): Stop pasting your writing rules into every ChatGPT chat. Load your Style Profile (or Master Prompt) into a ChatGPT Project once — your voice persists automatically across every writing session.
- [Why AI Writing That Works in Email Falls Apart in Slack](https://www.mywritingtwin.com/blog/writing-style-context-switch): Your writing style shifts measurably across platforms. Research shows stylometric models lose 55% accuracy when context changes, even with the same author.
- [The $5 Book That AI Detectors Can't Catch: Why Voice Matters More Than Tricks](https://www.mywritingtwin.com/blog/5-dollar-book-ai-detectors-cant-catch): A self-published author wrote a full book with Claude for $5. Pangram AI detector flagged 0% of passages as AI-generated. The secret was authentic voice.
- [Can You Tune Your Way Out of Average?](https://www.mywritingtwin.com/blog/can-you-tune-your-way-out-of-average): Temperature and top-p adjust token sampling variance, not style. LLM parameters can't move you out of the AI mean. Here's what actually does.
- [Your AI Writing Profile Doesn't Copy Your Mistakes (Unless You Want It To)](https://www.mywritingtwin.com/blog/your-ai-profile-doesnt-copy-your-mistakes): Most AI writing tools either copy your errors or erase your personality. Style Profiles do something different: preserve your voice, fix only what needs fixing.
- [What Is an AI Writing Profile? The Category That Doesn't Have a Name Yet](https://www.mywritingtwin.com/blog/what-is-an-ai-writing-profile): An AI Writing Profile captures your writing patterns across 50+ dimensions, enabling any AI to generate content in your voice. The definitive guide.
- [Stop Editing AI Output. Train It Instead.](https://www.mywritingtwin.com/blog/stop-editing-ai-output): Smart teams build 400-rule style guides and prune AI prompts like bonsai. A faster way exists: train AI with your writing upfront, not edit output after.
- [Your Writing Voice Changes When You Switch Languages](https://www.mywritingtwin.com/blog/multilingual-voice-preservation): Bilingual professionals shift voice, structure, and formality across languages. AI misses this entirely. Multilingual voice preservation fixes it.
- [Best AI Writing Prompts 2026: Templates for Every Use Case](https://www.mywritingtwin.com/blog/best-ai-writing-prompts-2026): Ready-to-use AI writing prompts for emails, reports, social media, and creative writing in 2026. Plus the one ingredient that makes every prompt work better.
- [ChatGPT for Work Setup Guide: Custom Instructions, Memory & Projects](https://www.mywritingtwin.com/blog/chatgpt-for-work-setup-guide): Set up ChatGPT for work in under an hour. Custom instructions, memory, projects, file uploads, and Writing DNA Snapshot deployment.
- [How to Deploy Your Writing Twin Across Every AI Platform](https://www.mywritingtwin.com/blog/deploy-writing-twin-across-ai-platforms): Learn how to deploy your writing style profile across ChatGPT, Claude, and Gemini. One document for consistent cross-platform AI writing that sounds like you.
- [How to Use AI to Edit and Improve Every Draft You Write](https://www.mywritingtwin.com/blog/use-ai-to-edit-communication-drafts): LLMs aren't just for generating text. Use ChatGPT, Claude, or Gemini to edit emails, reports, and messages — and keep your authentic writing voice.
- [How Every AI Model Writes: A Stylometric Comparison](https://www.mywritingtwin.com/blog/ai-model-writing-styles-compared): We analyzed 320 samples across Claude, GPT, and Gemini to measure 6 dimensions of writing style. Here's what the data reveals about each AI model's personality.
- [ChatGPT vs Claude vs Gemini: Which AI Writes Most Like a Human?](https://www.mywritingtwin.com/blog/chatgpt-vs-claude-vs-gemini-writing-comparison): We measured GPT-5.2, Claude Sonnet 4.5, and Gemini 3 Pro across 6 writing style dimensions using 320 samples. See which AI writes most like you in 2026.
- [How AI Models Write Differently: A Data-Driven Comparison](https://www.mywritingtwin.com/blog/how-ai-models-write-differently): We ran the same prompts through Claude, GPT-5.2, and Gemini, then measured 6 dimensions of writing style. The differences are bigger than you'd expect.
- [How AI Writes Differently in Japanese, French, and Spanish](https://www.mywritingtwin.com/blog/how-ai-writes-differently-across-languages): Our data from 320 samples across 4 languages reveals dramatic AI stylometric differences. French conciseness drops to 32; Spanish expressiveness to 59. Includes a correction: our Japanese expressiveness figure was a measurement error.
- [How to Make ChatGPT Sound Like You: The Complete Guide](https://www.mywritingtwin.com/blog/how-to-make-chatgpt-sound-like-you): Stop getting generic AI output. Learn how to make ChatGPT write in your authentic voice using Custom Instructions, Memory, Custom GPTs, and Style Profiles.
- [MyWritingTwin vs AI Writing Tools: The Missing Style Layer](https://www.mywritingtwin.com/blog/mywritingtwin-vs-ai-writing-tools): Jasper, Grammarly, Copy.ai, and ChatGPT all help you write. None capture your authentic style. Writing Style Profiles fill the gap they all share.
- [What Is a Writing Style Profile? Everything You Need to Know](https://www.mywritingtwin.com/blog/what-is-a-writing-style-profile): A Writing Style Profile maps your unique writing patterns across 50+ dimensions, creating a deployable document that makes any AI write in your authentic voice.
- [Which AI Model Writes Best in Each Language? A Data-Driven Answer](https://www.mywritingtwin.com/blog/which-ai-writes-best-per-language): We compared GPT-5.2, Claude, and Gemini across English, French, Spanish, and Japanese. The best model varies by language — and some results will surprise you.
- [Why AI Writing Sounds Generic — The Data Behind the Problem](https://www.mywritingtwin.com/blog/why-ai-writing-sounds-generic): We measured 320 AI writing samples across 5 models and 6 style dimensions. The data reveals exactly why every AI sounds the same — and it's not your prompting.
- [We Built a Writing Profile for Every AI Model — Here's What We Found](https://www.mywritingtwin.com/blog/writing-profiles-for-every-ai-model): We profiled 5 AI models like human writers. Claude, GPT, and Gemini each have a measurable writing personality — and none of them match yours.
- [How We Measure "Average AI" in Writing DNA](https://www.mywritingtwin.com/blog/how-we-measure-average-ai): Your Writing DNA radar chart compares you to 'Average AI.' Here's how we built that baseline — 320 samples, 5 models, 4 languages, and rigorous stylometry.
- [AI Content Writing Guide: Create Authentic Content at Scale](https://www.mywritingtwin.com/blog/ai-content-writing-complete-guide): How to use AI for content writing without losing your voice. Blog posts, marketing copy, social media, newsletters — and the scale vs. authenticity tradeoff.
- [How AI Detection Really Works (And Why Style Profiles Beat It)](https://www.mywritingtwin.com/blog/ai-detection-how-it-really-works): Technical breakdown of how GPTZero and Originality.ai detect AI text. Why humanizers fail long-term. Why authentic style profiles naturally evade detection.
- [Why AI Humanizers Don't Work (And What to Do Instead)](https://www.mywritingtwin.com/blog/ai-humanizer-better-approach): AI humanizers rearrange words but never fix the real problem: the text has no voice. Why synonym-swapping fails, and how Style Profiles solve it at the root.
- [Best AI Writing Tools 2026: A Stage-by-Stage Guide](https://www.mywritingtwin.com/blog/ai-productivity-tools-writing-stack-2026): The best AI writing tool for each stage of your workflow in 2026 — from ideation and research to drafting, editing, and publishing. Specific picks, not theory.
- [AI Writing Assistants Compared: The Definitive 2026 Guide](https://www.mywritingtwin.com/blog/ai-writing-assistant-comparison-2026): We tested ChatGPT, Claude, Gemini, Jasper, Copy.ai, and Writesonic on real writing tasks. Here's which ones deliver — and where they all fall short.
- [AI Writing for Teams: Stay On-Brand Without Micromanaging](https://www.mywritingtwin.com/blog/ai-writing-for-teams-guide): Marketing and content teams struggle with voice consistency across writers. Shared AI style profiles solve brand voice drift without endless style guides.
- [AI Editors for Writers: Which Ones Keep Your Voice?](https://www.mywritingtwin.com/blog/best-ai-editors-for-writers): A working writer tests AI editors and finds most strip away personal style. Which tools preserve your voice, and which flatten it into generic prose?
- [The Complete Guide to Maintaining Your Brand Voice with AI](https://www.mywritingtwin.com/blog/brand-voice-ai-complete-guide): Your brand voice is dissolving into AI-generated uniformity. Here's how to maintain it with voice documentation, AI style guides, and automated consistency.
- [The Professional's Guide to Using ChatGPT for Work in 2026](https://www.mywritingtwin.com/blog/chatgpt-for-work-guide): Compare the best AI writing tools for work — setup tips, real use cases, and how to keep your professional voice when using ChatGPT, Claude, and Gemini.
- [ChatGPT Memory vs. Style Profiles: A Deep Technical Comparison](https://www.mywritingtwin.com/blog/chatgpt-memory-vs-style-profiles-deep-dive): ChatGPT Memory remembers facts. Style profiles capture writing patterns. Here's the architectural difference—and why it matters for your AI output.
- [ChatGPT Project Instructions: Character Limit & Best Practices (2026)](https://www.mywritingtwin.com/blog/chatgpt-projects-complete-guide): The ChatGPT Projects instruction character limit, what happens if you exceed it, and the templates power users rely on for layered instructions. Updated 2026.
- [ChatGPT Voice Settings 2026: Control Its Tone & Writing Style](https://www.mywritingtwin.com/blog/chatgpt-voice-settings-complete-guide): Every ChatGPT setting that shapes how it writes: tone selector, custom instructions, memory, Projects, and Custom GPTs — what each does, where it fails, fixes.
- [ChatGPT vs Claude vs Gemini: Which AI Writes Best in 2026?](https://www.mywritingtwin.com/blog/chatgpt-vs-claude-vs-gemini-writing): We tested ChatGPT, Claude, and Gemini on real writing tasks — style handling, instruction following, long-form quality, and voice personalization.
- [Google Gemini for Writing: A Complete Guide for Content Creators](https://www.mywritingtwin.com/blog/gemini-ai-writing-guide): Master Google Gemini for writing. Learn its strengths, limitations, best prompting strategies, and how style profiles unlock Gemini's full writing potential.
- [How to Select Your Best Writing Samples for AI Analysis](https://www.mywritingtwin.com/blog/how-to-select-writing-samples): Not all writing samples are equal. Learn what makes a good sample for AI style analysis and why sample quality determines whether AI captures your voice.
- [AI Detection 2026: Why Detectors Fail and What Actually Works](https://www.mywritingtwin.com/blog/ai-detection-2026-guide): AI detection in 2026: why detectors fail, why humanizers are a losing strategy, and the ethical path forward. Strategic overview with Style Profile solution.
- [Build Your AI Writing Stack: The 4-Layer Framework](https://www.mywritingtwin.com/blog/ai-productivity-tools-writing-stack): Most professionals use 4-5 AI writing tools with no system connecting them. This 4-layer framework turns scattered tools into a coherent workflow.
- [50 AI Writing Prompts That Actually Sound Like You](https://www.mywritingtwin.com/blog/ai-writing-prompts-that-sound-like-you): 50 ready-to-use AI writing prompts for emails, reports, LinkedIn, and more. Each template includes a Style Profile slot that makes generic AI sound like you.
- [AI Editor Comparison 2026: 9 Tools Ranked](https://www.mywritingtwin.com/blog/best-ai-editors-2026): Side-by-side comparison of every major AI editor in 2026. Grammarly, ChatGPT, Claude, Jasper, and more scored on accuracy, voice, price, and integrations.
- [ChatGPT Projects Setup 2026: Step-by-Step + Instructions Template](https://www.mywritingtwin.com/blog/chatgpt-projects-setup-guide): Set up a ChatGPT Project in minutes: step-by-step walkthrough, a copy-paste instructions template, and the character limits and settings you'll actually hit in 2026.
- [How to Make AI Writing Sound Like You (5 Steps)](https://www.mywritingtwin.com/blog/how-to-humanize-ai-text): Step-by-step guide to making AI-generated text sound like your own writing. Skip the humanizer tools and teach AI your patterns with a Style Profile instead.
- [How to Make Google Gemini Write Like You: Setup Guide](https://www.mywritingtwin.com/blog/how-to-make-gemini-write-like-you): Google Gemini sounds generic without style instructions. Set up Gems, Workspace integrations, and Style Profiles to make Gemini write in your voice.
- [7 AI Writing Assistant Tricks That Save Hours Every Week](https://www.mywritingtwin.com/blog/7-ways-ai-can-improve-your-writing): From polishing a draft to handling a difficult email, here are 7 practical ways AI can transform your daily writing — and the one thing most people miss.
- [How to Build Custom Instructions That Actually Capture Your Voice](https://www.mywritingtwin.com/blog/how-to-build-custom-instructions-that-capture-your-voice): The 7 dimensions your custom instructions need to capture your voice. Most people miss 5. A diagnostic framework for voice-aware AI instructions.
- [The Median User Problem: Why AI Was Trained to Sound Like Everyone](https://www.mywritingtwin.com/blog/the-median-user-problem): AI output feels generic because it was optimized to be. The problem isn't your prompting — it's RLHF, a training process that averages out every voice.
- [10 Signs Your AI Writing Needs a Style Profile](https://www.mywritingtwin.com/blog/10-signs-ai-writing-needs-style-profile): Keep editing ChatGPT output to 'sound like you'? Your team can tell which emails are AI-generated? Here are 10 signs you need more than custom instructions.
- [ChatGPT for Business Leaders: Keep Your Executive Voice](https://www.mywritingtwin.com/blog/ai-writing-for-executives): Executives handle 100+ emails daily. ChatGPT can help — but only if it sounds like you. Here's how to use AI without losing your leadership voice.
- [How to Make Claude Sound Human, Not Robotic (2026 Guide)](https://www.mywritingtwin.com/blog/how-to-make-claude-sound-like-you): Stop editing generic AI drafts. The exact prompt and Project setup that makes Claude sound human — and like you — in under 10 minutes.
- [Best ChatGPT Custom Instructions for 2026 (Copy-Paste Templates)](https://www.mywritingtwin.com/blog/custom-gpt-instructions-complete-guide): The best ChatGPT custom instructions for 2026 — proven templates and real examples you can copy-paste today, plus the mistakes that make AI sound generic.
- [Science of AI Tone: How Machines Capture Your Writing DNA](https://www.mywritingtwin.com/blog/science-behind-voice-profiles): Most AI writing tools are black boxes. Here's the research behind how we make AI actually sound like you, grounded in decades of computational stylometry.
- [The Bilingual Professional's Guide to AI Writing](https://www.mywritingtwin.com/blog/bilingual-professionals-guide-ai-writing): AI writing tools fail non-native speakers worse than everyone else. Here's why—and how to make ChatGPT and Claude write in YOUR English, not generic English.
- [How AI Style Extraction Works: The Technology Explained](https://www.mywritingtwin.com/blog/how-style-extraction-works): An in-depth look at AI style guide technology. How we quantify something as qualitative as writing style, and why it works across ChatGPT, Claude, and Gemini.
- [Why ChatGPT Doesn't Sound Like You (And the Fix That Actually Works)](https://www.mywritingtwin.com/blog/why-ai-writing-doesnt-sound-like-you): You've tried custom instructions, personas, and example text. ChatGPT still sounds generic. Here's the real reason—and how to make ChatGPT write in your voice.

## Multilingual
- Available in English, Japanese, French, Spanish, and all languages
- Handles language-specific nuances: Japanese keigo levels, French tu/vous formality, cultural communication patterns