ChatGPT Writer
Devcraft Studio · ライティング
ChatGPT Writer is an AI writing assistant that runs as a browser extension and drafts emails, messages, and replies inside the sites where you already type. Think of it as an AI email writer that lives in your inbox. It's now branded Jetwriter AI, after a September 2025 rebrand, but the product underneath is the same tool that put ChatGPT into Gmail back in 2022. It works on Gmail, LinkedIn, Outlook, Slack, and most editable text boxes, and it's powered by a mix of GPT-5, Claude, and Gemini models rather than a single AI.
ChatGPT Writer について
What Is ChatGPT Writer
ChatGPT Writer is an AI writing assistant delivered mainly as a lightweight browser extension. You highlight text, right-click, or press a shortcut, and it rewrites, translates, shortens, or drafts a reply without leaving the page. The core idea is context: instead of copy-pasting text into a separate chatbot tab, the assistant reads what's on screen and responds to it.
The tool started in December 2022 as the first Chrome extension to connect ChatGPT with Gmail, aimed at people who hated writing email replies. The pitch was simple: rephrase text and draft answers without opening another tab. It has since grown into a multi-model assistant. Development comes from Devcraft Studio, a software agency based in Gurugram, India.
Two limits stand out. The free plan caps you at 15 responses per month, which is enough to test the writing quality and not much else. And you need an account to use it at all, which rules out the extension as a quick anonymous utility. The company also isn't shy about requiring a paid plan once you rely on it daily.
Getting Started
- Create a free Jetwriter AI account with email or Google sign-in. Nothing works until you're logged in.
- Install the extension from the Chrome Web Store, or add it to Edge, Brave, Opera, or Vivaldi. A web app covers browsers the extension doesn't support.
- Open Gmail, LinkedIn, or any editable field, then either click the extension icon or use the keyboard shortcut (Ctrl+Shift+K on Windows).
- Highlight text to fix grammar, translate, summarize, or rewrite it, or ask the assistant to draft a reply in your voice. Tone and length are adjustable in one click.
- Copy the output into your draft, or let Gmail auto-draft replies save it straight to your inbox.
AIツール情報
ChatGPT Writerの料金、対応プラットフォーム、性能を簡単に確認できます。
こんな人におすすめ
このツールが最も力を発揮するユーザー、タスク、シーン。
ユーザー
- Sales and support staff who answer dozens of similar emails a day
- Non-native English speakers
- Recruiters, freelancers, and anyone who writes personalized outreach
タスク
- Drafting email replies in Gmail
- Rephrasing and shortening text
- Summarizing a long web page or document
シーン
- Clearing a backed-up inbox on a Monday morning
- Answering messages on WhatsApp Web, LinkedIn, or a support desk like Freshdesk without switching tools.
- Working across languages
主な機能
Email and message replies that read the thread
The extension hooks into Gmail, Outlook, LinkedIn, WhatsApp Web, Slack, Zoho, Freshdesk, and Zendesk. When a message needs an answer, it drafts one based on what was actually said. That's the feature that made the tool popular, and it's still the reason most people install it. No blank page. No starting from scratch.
AI Profile with memory
You build a profile that describes your tone and style, and the assistant applies it to everything it writes. A separate memory feature remembers past conversations, so you don't restate the same context twice, which matters when you're drafting for the same client every week. The output sounds less like a generic chatbot and more like something you'd actually send. It's a real difference on client email.
Gmail auto-draft
Rather than waiting for you to click, the extension can pre-write a reply directly in your Gmail inbox whenever an email needs one. You control how often it runs in settings, and plans cap it at 50 or 70 auto-drafts per day. It turns reply-writing into reply-reviewing. That's the whole point.
Multiple AI models in one place
Regular tasks run on GPT-5 mini and Gemini 3 Flash, while heavier work can use Claude Opus or Sonnet and higher GPT-5 tiers. You can switch models mid-conversation, which helps when a quick rewrite and a long analysis need different strengths. The trade-off is the quota system: advanced-model responses are metered separately from the unlimited regular ones.
Tone and length controls
One click shifts a draft between formal, friendly, shorter, or longer. It's a small feature that saves a lot of manual editing, particularly when the same message has to go out to different audiences. Why rewrite the same note three times when the tone switch does it?
Chat with pages and documents
You can ask questions about the page you're reading, or attach files and chat with them. Summaries, key details, and direct answers come back without opening another window. Live web access lets it pull current information instead of relying only on training data.
Transforms on any site
Select any text and the right-click menu offers grammar fixes, translation, summarization, and explanation. You can add custom actions for prompts you use often, and disable the defaults you don't. All languages are supported for both input and output. Every site, every language, one menu.
メリットとデメリット
メリット
- Works inside Gmail, LinkedIn, Outlook, and other tools you already use, so there's no copy-paste step.
- Personalized output via AI Profile and memory, which beats generic chatbot replies for email.
- Several leading models behind one subscription, switchable during a chat.
- Lightweight extension (under 1MB) that doesn't noticeably slow the browser.
- Official privacy stance: data isn't shared with third parties or used for AI training, and it's encrypted in transit with TLS 1.2 or higher.
デメリット
- The free plan stops at about 15 responses a month, which is too little for regular work, and an account is required before you can use anything. Not ideal if you just want to try it on one email.
- Paid plans start at $18/month, and some reviewers call that steep for what's essentially an extension sitting over tools you may already pay for.
- Recent user ratings on the Chrome Web Store have slipped below the all-time average, with complaints about output reliability and unrewarded prompts.
- Advanced-model usage is capped monthly, so heavy users on Elite and Ultra can hit a wall before the month ends.
よくある質問
There's a free plan, but it's limited to around 15 regular-model responses per month. You can test the writing quality and daily workflows with it, and anything more consistent needs a paid plan. ChatGPT Writer pricing breaks into two paid tiers: Elite runs $18/month ($14/month billed yearly) and Ultra is $39/month ($29/month yearly). Annual billing saves 22% or 25% depending on the tier.
関連コンテンツ
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