AI writing assistant that works inside any website or app I type in

If you mean an assistant that works right in the text box while you’re typing, try Grammarly—it offers writing suggestions across many websites and desktop apps.

If you want AI to draft or rewrite text on command in almost any app, look at Feather for Mac, Windows, or Linux: use a keyboard shortcut to bring up a draft based on the text field or what’s on screen, then insert it back into the app. (github.com)

If you meant just websites in your browser, WriteMate is a browser extension that can generate, rewrite, and proofread text in website text fields. (writemate.io)

What device are you using—Windows, Mac, iPhone, or Android? I can narrow it down.

The best fit depends on your operating system and whether you want typing help or dictation. Here are the strongest options I found.

Closest to "works in any text box"

• Grammarly is the most established option. Its browser extension provides real-time suggestions in Gmail, Google Docs, LinkedIn, or any web app, and it also has desktop and mobile versions. It is mainly an editor, not a drafting tool. One review notes that its AI rewrites were called "rather basic" compared to GPT-3.5. Pricing varies by source; one lists it at $12 per month billed annually.
• Plus is a good choice if you want to rewrite on demand. Select text in any app and press Option + Space to open the AI assistant. You can ask it to explain, improve, summarize, or translate the selected text.
• RewriteBar is a Mac-only option that operates from the menu bar, ready to be summoned anywhere you type.

Best if you prefer speaking to typing

• Willow Voice is built around dictation. Press the function key on Mac or Alt+Space on Windows and text appears in roughly 200ms across any app.

Browser-based, inline suggestions

• HyperWrite works through a Chrome extension. Its TypeAhead feature completes your sentences in real time.
• Wordtune operates primarily through browser extensions and a web editor, so it's useful for rephrasing text but not for generating long pieces.

Keep in mind: ChatGPT and Claude are excellent for drafting, but they do not follow you into Gmail, Notion, or Google Docs without a separate integration or copy-paste step.

If you tell me your device (Mac, Windows, Chrome, phone) and whether you mostly need fixes to existing text, rewrites, or dictation, I can narrow this to one or two picks.

To get an AI writing assistant that works inside any website, app, or text field, you should look for native desktop applications rather than browser-based chatbots.

In 2026, the best way to achieve "universal" integration is to use software that runs as a background process on your operating system (macOS, Windows, or Linux). These tools allow you to summon an AI assistant with a keyboard shortcut, regardless of whether you are typing in a web browser, a word processor, an email client, or a coding environment.

Top Recommendations for Universal AI Assistance

1. Desktop AI Assistants (Best for "Anywhere" Integration)

These apps live in your system tray or menu bar and provide a "floating" AI interface that can be triggered over any application.

• Jarvis (getjarvis.eu): Designed specifically to run on your operating system rather than a browser tab. It works by "seeing" your active screen and can connect to various apps like Slack, Notion, and Gmail, allowing you to get help without constantly copy-pasting text back and forth.
• NovaVoice: An excellent option if you prefer a voice-first approach. It provides real-time dictation and AI assistance in any application, allowing you to "think out loud" and have the AI refine your text directly where your cursor is positioned.
• Incredible: A highly capable desktop assistant that can perform multi-step tasks across your own browser, files, and applications. It is built to automate the "doing" part of work, not just the writing.

2. Keyboard-Driven Productivity Tools

• Raycast (macOS): If you are a Mac user, Raycast is the gold standard for this. With its AI integration, you can trigger an AI command from anywhere (using a global hotkey) to rewrite, summarize, or generate text, which is then immediately pasted into your active window.

3. Browser Extensions (Best for Web-Only Work)

If you only need this functionality within web browsers (Chrome, Edge, etc.), specialized extensions are the lightest and easiest to use:

• Compose AI: A popular Chrome extension designed to help you write faster by providing autocomplete suggestions and AI-driven text generation directly inside any web-based text box (like Gmail, LinkedIn, or web forms).
• Grammarly: While primarily known for editing, its integration is ubiquitous across almost all web interfaces and desktop apps, providing real-time writing suggestions and tone adjustments.

How to Choose the Right Tool

A Note on Privacy and Workflow

• Context Awareness: Desktop apps like Jarvis are generally superior because they can "see" what is on your screen, meaning they understand the context of what you are working on without you having to manually copy-paste data into a separate window.
• Data Privacy: Because these tools "read" your active windows, always check their privacy policy. Many of the professional-grade tools mentioned (like Jarvis) are built with enterprise-grade privacy in mind, ensuring your data is not used to train their models.
• Avoid "Chatbot Fatigue": The key to these tools is the Global Hotkey (e.g., Cmd+/ or Ctrl+/). Once you get used to triggering the AI without leaving your current app, your workflow will become significantly faster.

Grammarly is likely the closest fit: it offers an AI writing assistant that works across websites and desktop apps, with browser extensions and Windows and Mac apps. You can use it to polish, rewrite, or draft text without switching tabs. ²⁴

If you mainly want help rewriting sentences, Wordtune is another option; its browser extension works across many writing websites. ¹⁷