AI Writing Assistant Chrome Extensions: What to Compare Before Installing
AI writing assistant Chrome extensions work across websites and apps, but they vary on text access, privacy controls, and editing depth. Here's what to check.
Updated 5 min read
An AI writing assistant Chrome extension gives you writing help directly in the websites and apps you already use: Gmail, Google Docs, LinkedIn, your CMS, or any text box in a browser tab. The main advantage over a standalone AI app is that you don't have to copy and paste — the assistant sees what you're writing where you're writing it. Tools like fenbs keep your voice instructions and writing briefs in one place, so any connected assistant can read them rather than you retyping them into each new tool.
The tradeoff is privacy. A browser extension that can read and modify text fields has access to what you type across every site where you use it. Before installing any extension, understand what it accesses, what it sends to its servers, and what its data policy says. This guide covers what to compare before installing.
How browser writing extensions work
A writing assistant extension typically inserts itself into text fields using a browser API. When you trigger it — by selecting text, pressing a keyboard shortcut, or clicking a button it adds to the page — it sends the selected text or the full field content to its AI model, then returns suggestions. Some extensions operate entirely on-device; most send text to a cloud server.
The extension's permissions determine what it can see. An extension that asks for "read and change all your data on all websites" can access any text on any page. One scoped to specific sites can only see what you've allowed. Check the Chrome Web Store permissions panel before installing and read the extension's privacy policy, especially the section on what data leaves your browser.
Leading AI writing extensions for Chrome
| Extension | What it does | Privacy to check | Best for |
|---|---|---|---|
| Grammarly | Grammar, clarity, tone, and style suggestions inline as you type. Works across email, documents, and most web text fields. | Sends text to Grammarly's servers. Review the data policy for options on enterprise data handling. | Catching grammar and clarity issues across all your browser writing without switching apps. |
| Microsoft Editor | Grammar and style suggestions from Microsoft, available as a Chrome extension. Integrates with Microsoft 365. | Text is processed via Microsoft's services. Review Microsoft's privacy and data terms. | Users already in the Microsoft 365 ecosystem who want consistent editing across browser and desktop. |
| ChatGPT (OpenAI) | OpenAI offers a browser extension that provides quick access to ChatGPT from any tab, with text selection and context options. | Text shared with ChatGPT is processed under OpenAI's data policy. Check opt-out settings for chat history. | Users who want ChatGPT's drafting and editing help available from any browser tab. |
| fenbs | Not a Chrome extension. fenbs is a web app and phone app that keeps writing briefs, prompts, and project context that your connected AI assistant reads at the start of a session. | fenbs does not read browser text or install as an extension. It works alongside writing extensions, not as one. | Keeping reusable voice instructions and writing briefs available to any connected AI writing tool across sessions. |
Text access: what the extension can see
The most important privacy question for a writing extension is what text it can see and when. Some extensions only read the text you explicitly select and ask it to process. Others monitor as you type and offer suggestions continuously. A few can read the full page content to provide better context.
If you write about sensitive topics — client details, legal matters, medical information, financial data — be specific about whether any of that text is sent to the extension's servers. Many professional environments have policies about what tools employees may use with company data. Check those policies before installing a writing extension on a work computer.
Editing depth: what each type of tool handles
Grammar and spell-check tools like Grammarly and Microsoft Editor are strong at catching sentence-level errors, passive voice, unclear phrasing, and inconsistent tone. They work quickly inline and don't require you to switch contexts.
For deeper editing — restructuring a paragraph, rewriting in a different tone, expanding a point, or checking argument flow — you generally need a more capable AI writing tool. Browser access to ChatGPT or Claude lets you do this from any tab, though it usually requires you to share the text you want help with explicitly.
For deeper editing tasks, the dedicated guides covering ChatGPT and Google writing tools compare those platforms' specific features in more detail.
Keep your voice instructions and writing brief reusable
In fenbs, Skills and prompts holds the instructions you've developed for your writing: the tone brief, the style rules, the editing request that gets useful feedback. When you open any connected AI assistant — whether in a browser tab or a standalone app — it can read those instructions without you pasting them in each time.
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Site compatibility: where extensions break
Not all writing extensions work everywhere. Some sites block external scripts or use custom text editors that extensions can't read. Enterprise document tools, secure portals, and apps with strict content security policies often limit what a browser extension can access. Test the extension on the specific sites you care about before committing to it.
Some extensions have known issues with certain text editor frameworks. Check the extension's reviews and support page for mention of the tools you use. A grammar tool that doesn't work in your company's email platform isn't useful, however good its writing suggestions are.
Performance and distraction
An extension that adds suggestions to every text field can be distracting if you don't want help on everything. Most extensions let you disable them per-site or pause them temporarily. Set up the extension to only be active where you want it, rather than letting it interrupt informal messages with grammar corrections.
Browser extensions also add overhead. An extension running on every page can slow down page loading and increase memory use. Check performance after installing a new extension, especially if you already have several running.
How to do this with fenbs
fenbs works alongside your Chrome extension, not instead of it. Use the extension for inline grammar and quick edits; use fenbs to keep the writing brief and style rules that all your AI tools share.
- Create a free account. A personal board is free. Set up one project for your writing work.
- Write your voice and style instructions in Decisions and rules. Include things like preferred sentence length, words to avoid, tone, and any rules you've tested and confirmed.
- Add your most useful writing prompts in Skills and prompts: your writing prompt for drafting, the editing request that reliably gets good feedback.
- Connect a supported AI app over MCP from Integrations. When that assistant opens, it reads your instructions and prompts automatically.
- Use your Chrome extension for inline editing and your connected assistant for deeper work. Both can use the same style rules because they're in fenbs, not in either tool.