If you write in a browser — emails in Gmail, documents in Google Docs, notes in Notion — you've probably thought about adding an AI writing assistant to Chrome. The market has grown dramatically over the past year, and the number of extensions claiming to improve your writing has gone from a handful to dozens.
The problem is that most of them weren't built around your writing workflow. They were built around their own product interface.
This guide compares five of the most widely-used AI writing assistant Chrome extensions in 2026: Grammarly, Monica, Sider, QuillBot, and TextBoi. We'll go beyond feature checklists and look at what daily use actually feels like — including where each tool quietly slows you down.
Why AI Writing Extensions Are Becoming Popular
Browser extensions occupy a strategic position in the AI writing tools landscape. Unlike desktop apps that live separately, extensions install directly into Chrome — right where most modern knowledge work happens.
In 2026, the average professional writes in:
- Gmail or Outlook Web
- Google Docs or Microsoft 365 Online
- Notion, Confluence, or Linear
- Slack or Teams in the browser
- CRMs like HubSpot or Salesforce
Browser-native AI tools have a natural advantage here. They see your text, they have context about what you're writing, and they can act inline. This is how Grammarly built its dominant position, and why so many tools have followed.
The key question, though, is: what kind of AI assistance do you actually want?
Some tools correct you passively as you type. Others open a powerful sidebar packed with AI capabilities. A newer category focuses on eliminating workflow friction entirely — keyboard-first, no panel, no context switch.
Understanding that difference is more useful than comparing feature lists.
Quick Comparison Table
| Feature | Grammarly | Monica | Sider | QuillBot | TextBoi |
|---|---|---|---|---|---|
| Core approach | Passive inline correction | AI sidebar assistant | AI sidebar + multi-model | Paraphrasing tool | Shortcut-first inline editor |
| Grammar correction | ✔ Best in class | ✔ Yes | ✔ Yes | ✔ Yes | ✔ Yes |
| Translation | ✖ No | ✔ Yes | ✔ Yes | Limited | ✔ 150+ languages |
| In-place text replacement | Partial | ✖ Sidebar required | ✖ Sidebar required | ✖ Copy-paste required | ✔ Full inline replace |
| OCR (fix text from images) | ✖ No | ✖ No | ✖ No | ✖ No | ✔ Yes |
| Keyboard shortcut workflow | ✖ | ✖ | ✖ | ✖ | ✔ Cmd/Ctrl+C+C |
| Works outside browser | Partial (desktop app) | ✖ Chrome only | ✖ Chrome only | ✖ Chrome only | ✔ Full desktop app included |
| AI model quality | Proprietary | GPT-4o, Claude | GPT-4o, Claude | QuillBot AI | GPT-4.1, GPT-5, 4o |
| Free tier | Very limited | Yes | Yes | Yes | 150,000 chars/month |
| Paid price | ~$12/month | ~$9/month | ~$5/month | ~$10/month | $5/month |
Detailed Reviews
1. Grammarly
What it does: Grammarly is the most established browser-based grammar assistant. Its Chrome extension runs passively in the background, scanning text fields for grammar, punctuation, spelling, and style issues. As you type, colored underlines appear — clicking them surfaces suggestions you can accept or dismiss.
What it does well: Real-time correction while typing is Grammarly's core strength, and it does it better than anyone else. The Chrome integration is broad and reliable — Gmail, Google Docs, LinkedIn, and most major writing platforms work seamlessly. The suggestion quality for English prose is consistently high, and the interface is mature enough that it rarely gets in the way.
Where it falls short: Grammarly is an English-first tool. If you write in other languages or need translation, it doesn't help. The paid plan runs around $12/month annually — one of the higher prices in this category for what is fundamentally a grammar tool. For AI rewriting or generative features, you're looking at Grammarly GO, which is a separate product.
The interaction model also has a compounding cost that's easy to overlook. You see an underline. You stop typing. You hover. You read the suggestion. You decide. You click or dismiss. For a document with 40 flagged items, that's 40 individual micro-decisions interrupting your writing flow. Grammarly is passive until you engage with a suggestion — then suddenly it's demanding your attention.
Verdict: Still the default recommendation for English-only browser writing. Unmatched passive correction. Less compelling once you factor in price and the click-by-click interaction model.
2. Monica
What it does: Monica is a full-featured AI assistant Chrome extension built around a sidebar interface. It offers chat with GPT-4o and Claude, writing help, webpage summarization, translation, and a library of task presets. You trigger it by clicking the Monica icon or using a shortcut to open the side panel.
What it does well: The breadth of capability is genuinely impressive. Within one extension, you can ask questions about a webpage you're reading, summarize a long article, get writing suggestions, translate content, and run custom AI prompts. For users who want an AI research companion built into their browser, Monica delivers that experience well.
Where it falls short: The fundamental workflow pattern is a sidebar, and that creates friction for pure editing use cases. To improve text you've already written, you copy it, paste it into the Monica chat, interpret the output, copy the revised version, and paste it back into your document. Every single edit is a five-step process.
The sidebar also takes up real estate — on a 13-inch laptop, having Monica open covers a meaningful portion of the screen. It's designed to be consulted, not to edit inline. If your primary goal is improving writing speed, the sidebar model works against you.
Verdict: Excellent for users who want AI assistance while researching and browsing. Less suited to writers who want to edit at speed without breaking their document focus.
3. Sider
What it does: Sider is structurally similar to Monica — a multi-model AI sidebar for Chrome. It offers chat, translation, writing assistance, and supports switching between GPT-4o, Claude, and other models. Like Monica, you access it via a sidebar panel.
What it does well: Sider's multi-model support is a genuine differentiator. Being able to run the same prompt through GPT-4o and Claude and compare outputs has real value for users who care about AI output quality. The interface is clean, and the writing presets (tone adjustment, summarization, paraphrase) are well-organized.
Where it falls short: The same core limitation applies: every edit is a round-trip. Select, copy, open sidebar, paste, get output, copy output, switch back, paste into document. For one-off research tasks, this is fine. For a day of heavy writing work, the cumulative overhead adds up.
Some users also report that sidebar AI tools tend toward generic rewrites — polished, but not always voice-preserving. When the AI is working from a detached copy of your text rather than in the context of your document, it sometimes loses the thread of your writing style.
Verdict: Strong option for multi-model AI access in the browser. Same structural friction as Monica for inline editing use cases.
4. QuillBot
What it does: QuillBot made its name as a paraphrasing tool, and its Chrome extension brings those capabilities into the browser. It offers grammar checking, paraphrasing with targeted modes (Standard, Fluency, Formal, Academic, Creative), summarization, and basic translation.
What it does well: For paraphrasing with tone control, QuillBot still has a well-designed mode system. The ability to target "Formal" or "Academic" specifically — rather than generic rewriting — is useful for students and professionals who write in defined registers. The extension integrates into Chrome reasonably well, with a popup interface that appears over your current page.
Where it falls short: Grammar correction is a secondary feature, and the accuracy doesn't reach Grammarly's level. Translation is limited compared to dedicated tools. And in 2026, QuillBot's paraphrasing quality is no longer a differentiator — GPT-4-class models available in other tools match or exceed it, with better workflow integration.
The editing experience also requires the same copy-paste pattern as other sidebar tools. You don't edit inline; you work in QuillBot's own interface and bring the result back.
Verdict: Still worth considering for paraphrasing workflows, especially with the Academic and Formal modes. Less compelling as a general-purpose writing assistant in 2026.
5. TextBoi
What it does: TextBoi takes a different approach entirely. It started as a native desktop app — an AI writing assistant that works system-wide on macOS and Windows. Its Chrome extension brings the same philosophy to the browser: select text, press Cmd+C+C (Mac) or Ctrl+C+C (Windows), and the selected text is replaced in-place with corrected, rewritten, or translated output.
No sidebar. No copy-paste. No dialog boxes to dismiss. Just the shortcut.
Watch the Chrome extension demo:
How the workflow feels: You write your draft. You select the paragraph. You press the shortcut twice. The text updates in-place. You didn't open a panel, switch focus, or touch the clipboard. You just keep writing.
This sounds like a small thing. Across a day of editing, it isn't.
What it does well:
In-place replacement — Text edits happen exactly where your cursor is. When the AI finishes, you're still in your document, on the same line, without any navigation needed.
Grammar correction and rewriting — Standard AI writing improvement via GPT-4.1, GPT-5, and GPT-4o. The models are comparable to what Monica and Sider offer; the difference is how you access the output.
Translation into 150+ languages — Same shortcut, same in-place workflow. Select a paragraph in English, press Cmd+C+C, choose Translate → Korean (or whichever language you need), and the Korean text appears in your document. This works well for replying to international emails without ever leaving Gmail.
OCR capture — A capability none of the other tools in this comparison offer. Using Cmd+Shift+C (Mac) or Ctrl+Shift+C (Windows), you drag to capture any text visible on your screen — including text embedded in images, screenshots, scanned PDFs, or content in apps where text isn't selectable. TextBoi reads it with OCR and applies the same correction, translation, or rewrite workflow.
Works in Gmail, Google Docs, Notion, and nearly any text field — If Chrome can render it as editable text, the extension can work with it.
Desktop app included — TextBoi isn't just a Chrome extension. The installation includes the full desktop app, which extends the same shortcut workflow to every application on your computer — Slack desktop, Figma, native email clients, PDF readers. The Chrome extension and the desktop app share the same account and character quota.
Where it falls short: TextBoi is not passive. It does not flag issues as you type or highlight grammar problems in the background. The editing is entirely on-demand — you have to notice a problem, select the text, and trigger the shortcut. Users who want continuous monitoring while they write will find this model requires a different discipline.
It also doesn't offer AI chat, sidebar search, document analysis, or webpage summarization. It's deliberately narrow — designed to do one thing (edit text) as quickly as possible, and nothing else.
Free tier: 150,000 characters/month on GPT-4o mini — more generous than Grammarly's free plan. Paid: $5/month for GPT-4.1, GPT-5, and GPT-4o.
Best Extension for Different Use Cases
You want grammar correction while you type, no workflow changes → Grammarly. This is still what it does best. Install it, forget it's there, and let it catch errors passively.
You want an AI assistant to consult while researching or reading online → Monica or Sider. The sidebar model is well-suited to this use case — you're already consulting, so the panel fits the workflow.
You need to paraphrase academic or formal writing with tone control → QuillBot. The mode system (Academic, Formal, Creative) is still one of the most targeted paraphrasing tools available.
You write heavily in Gmail, Google Docs, or Notion and want the fastest editing workflow → TextBoi. The inline shortcut replaces the entire copy-paste round-trip.
You need OCR — fixing or translating text from images, screenshots, or locked apps → TextBoi (the only option in this comparison).
You write in multiple languages or communicate internationally → TextBoi. 150+ languages in the same keyboard shortcut.
You want a single extension that covers browser work and native desktop apps → TextBoi. The Chrome extension and desktop app are part of the same product.
Why Workflow Speed Actually Matters
The debate about "which AI model is better" is important, but it misses the more practical question for most writers: how much friction does the tool add?
Consider what sidebar-based editing actually looks like in practice:
- Finish drafting a paragraph
- Select the text
- Open the sidebar
- Wait for context to load
- Read the AI's rewritten version
- Copy the output
- Switch focus back to the document
- Find your location in the document
- Select the original text again
- Paste the replacement
That's a 10-step process for one edit. If you do that 20 times across a workday — emails, docs, Slack messages — you've spent the equivalent of 20 focused minutes on tool overhead.
Passive tools like Grammarly are more efficient for the corrections they flag, but the click-per-suggestion model has its own cost. A heavily marked-up document requires dozens of individual micro-decisions that fragment writing flow.
The shortcut approach TextBoi uses collapses editing to two steps: select, trigger. The AI does the rest. That reduction in friction isn't the most exciting technical story, but it's one of the most impactful differences in terms of actual daily output.
This is why keyboard-first tools are gaining traction among heavy writers even when their raw AI capabilities don't obviously exceed what's available in full-featured AI suites. The accessible tool wins.
Final Verdict
Grammarly remains the right choice for English writers who want passive correction without changing their workflow. The price is high for what it does, but the quality and integration are genuinely mature.
Monica and Sider are strong for users whose work combines browsing, research, and writing. If you find yourself frequently asking AI questions while reading online content, the sidebar model fits naturally.
QuillBot still has a use case in paraphrasing-heavy workflows, particularly in academic or formal contexts where tone targeting matters. But as a general AI writing assistant, it's being outpaced by tools with broader capability.
TextBoi is the tool to try if you've noticed that the actual bottleneck in your writing workflow isn't AI quality — it's the number of steps between you and a polished result. The inline shortcut model is genuinely different from everything else on this list, and for high-volume writers in Gmail and Google Docs, it removes a class of friction that other tools don't address.
In 2026, the honest answer is that there's no universal winner. There's the right fit for how you actually work.
If you mostly type in English and want a safety net: Grammarly. If you want AI assistance across browsing and writing: Monica or Sider. If you want to write fast without breaking your flow: TextBoi.
If you write in Gmail, Google Docs, or Notion and the copy-paste workflow is something you'd rather skip, try TextBoi — the free tier is generous enough to test in your real workflow without committing to anything.
❓ Frequently Asked Questions
What is the best AI writing assistant Chrome extension in 2026?
It depends on your workflow. Grammarly is best for passive grammar correction while typing. Monica and Sider are best for all-in-one AI sidebar assistance. TextBoi is best for fast inline editing without copy-pasting — especially for Gmail and Google Docs power users.
Is there a Chrome extension that translates and replaces text inline?
Yes. TextBoi's Chrome extension translates text directly in-place. Select the text, press Cmd+C+C (Mac) or Ctrl+C+C (Windows), choose Translate, and the result replaces your selection right where it was — no sidebar or copy-paste required.
Can any Chrome extension read and fix text in screenshots or images?
TextBoi is the only tool in this comparison with built-in OCR. Using Cmd+Shift+C (Mac) or Ctrl+Shift+C (Windows), you can drag to capture any text visible on screen — including images, scanned documents, and locked apps — and instantly correct or translate it.
Does Grammarly work in Gmail and Google Docs?
Yes. Grammarly's Chrome extension works in Gmail and Google Docs, as well as most web-based text fields. TextBoi also works in Gmail and Google Docs, using a shortcut to fix your entire draft at once rather than flagging issues inline.
What is the difference between sidebar AI tools and shortcut-based tools like TextBoi?
Sidebar tools like Monica and Sider require you to copy text, paste it into a panel, review the output, copy the result, and paste it back into your document. Shortcut-based tools like TextBoi collapse this to two steps: select text, press the shortcut. Over a full day of writing, the difference in friction compounds significantly.
Is TextBoi's Chrome extension free?
TextBoi's free tier includes 150,000 characters per month using GPT-4o mini — enough for most daily writing workflows before upgrading. Paid plans start at $5/month and unlock GPT-4.1, GPT-5, and GPT-4o.
Which AI Chrome extension is best for non-English writing?
TextBoi supports 150+ languages with the same keyboard shortcut — you can translate, correct, or rewrite in Spanish, Japanese, French, Korean, German, and more without changing tools. Grammarly is primarily English-focused. Monica and Sider offer translation but require a sidebar interaction.