Which AI Chrome extension is best in October 2026?
Sider's Chrome Web Store listing carries the largest rating pool of the 12 extensions we read on 12 October 2026. It's a sidebar that chats with GPT, Claude, Gemini, DeepSeek and Grok about the page, PDF or video you have open. Its privacy section declares just two kinds of user data, identity and website content. The surprise is one row down.
Anthropic's Claude extension has more than three times Sider's users and the lowest rating here, 2.9 from 1,800 ratings. Its listing also declares six kinds of user data, web history and website content among them, the most of the 11 listings we read. And it does nothing on a free account. Anthropic's help center says "Claude in Chrome is available for all paid plans (Pro, Max, Team, and Enterprise)." Claude's pricing page puts Pro at $20 a month or $200 a year. Grammarly has the most users of the 12, 40 million, but it's a writing tool first.
Here's the pick by job, from the listings and pricing pages on 12 October 2026:
- Best overall: Sider. It reads the page with five model families, and Nano costs $100 a year.
- Best browser agent: Claude in Chrome. It reads, clicks, types and fills forms in a side panel, from Claude Pro at $20 a month.
- Best with nothing to install: Gemini in Chrome. It's built into Chrome and reads up to 10 open tabs.
- Best for writing: Grammarly. Its free plan gives 100 AI prompts a month, and Pro is $12 a month.
- Best for automation: HARPA AI. It runs 100+ page commands and watches pages for changes.
- Best free sidebar: MaxAI. It offers unlimited chat on its fast free model plus 3 Pro chats a day.
- Best for reading and YouTube: Glasp. Its free plan summarizes 3 YouTube videos a day.
How do the top AI Chrome extensions compare on price and free use?
The 12 AI Chrome extensions split three ways: sidebars that chat about the page (Sider, Monica, Merlin, MaxAI), agents that act on it (Claude, Gemini, HARPA), and single job tools (Grammarly, QuillBot, Glasp, ChatGPT search). We read users, rating and last update on each Chrome Web Store listing, and prices on each vendor's pricing page, all on 12 October 2026. Prices are in US dollars unless the cell says otherwise.
| Extension (maker) | What it does on the page | Users, rating (ratings) | Last updated | Free use | Cheapest paid plan |
|---|---|---|---|---|---|
| Sider (Vidline) | Sidebar chat with GPT, Claude, Gemini, DeepSeek and Grok; page, PDF and YouTube summaries | 5M, 4.9 (114.5K) | 9 Oct 2026 | No free plan on its pricing page | Nano, $100 a year |
| Claude (Anthropic) | Reads, clicks, types and fills forms in a side panel | 18M, 2.9 (1.8K) | 8 Oct 2026 | None, paid Claude plans only | Pro, $20 a month or $200 a year |
| Gemini in Chrome (Google) | Built into Chrome; reads the current tab or up to 10 tabs | Built in, no listing | Ships with Chrome | Google's help page names no paid plan | Auto browse: Google AI Pro or Ultra, US preview |
| Grammarly | Drafts, rewrites and changes tone in any text box | 40M, 4.5 (43.2K) | 7 Oct 2026 | 100 AI prompts a month | Pro, $12 a month |
| QuillBot (Course Hero) | Paraphraser, humanizer, AI detector and AI Cursor in the page | 6M, 4.7 (6K) | 8 Oct 2026 | Not read, pricing page blocks automated reads | Not read |
| Monica (Butterfly Effect) | Sidebar chat, page and YouTube summaries, translation, Browser Operator | 3M, 4.9 (32.3K) | 6 Aug 2026 | 40 basic model queries a day | Pro, $99 a year, 200 advanced queries a month |
| Merlin (Foyer Tech) | Sidebar chat on any page, summaries, Gmail assistant | 900K, 4.8 (8.8K) | 5 Oct 2026 | "Limited access", no numbers given | Pro, $228 a year |
| MaxAI | Sidebar chat, email and message replies, translation | 700K, 4.7 (14.5K) | 23 Aug 2026 | Unlimited free model chat, 3 Pro chats a day | Pro, $30 a month or $12 a month billed yearly (limited time) |
| HARPA AI | 100+ page commands, scraping, page change monitors | 400K, 4.7 (3.2K) | 29 Jun 2026 | Demo, 10 messages a day | For Everyone, CA$19 a month billed yearly (shown in local currency) |
| Glasp | Highlights, article and YouTube summaries | 500K, 4.5 (990) | 4 Sep 2026 | 3 YouTube summaries a day, 20 AI chat credits a month | Pro, $150 a year |
| ChatGPT search (OpenAI) | Makes ChatGPT search Chrome's default search engine | 4M, 3.3 (1.6K) | 18 Dec 2024 | Free, needs a chatgpt.com login | None needed |
| Whizi AI (Whizi) | Toolbar popup chat with Whizi AI; doesn't read the page | 3 users, 5.0 (1) | 26 Aug 2026 | 10 messages a day | Starter, $15.99 a month |
Two rows age badly. OpenAI hasn't updated ChatGPT search since 18 December 2024, and it only swaps your address bar search to ChatGPT. It doesn't read pages. Monica's listing was last updated in August, and its description still names GPT-5.2 and Claude 4.5 Sonnet. MaxAI's pricing page says "all payments are final and non-refundable". Try the free plan first.
Two names from other lists are missing on purpose. Perplexity's own extension listing showed "Item not available" on 12 October 2026, and a fake "Search for perplexity ai" extension was taken down in June 2026 after Microsoft reported it to Google. Meeting recorders such as Fireflies and Otter are out too. They record calls instead of reading the page.
Merlin publishes the vaguest free plan. Its pricing page lists "Limited access to Basic models" with no number, and says Pro gives at least 30x the usage of Free. If you already pay for one of the sidebars, the Monica alternatives and Merlin alternatives pages price a switch in more detail.
Which AI Chrome extensions collect the most data?
Claude's extension declares the most user data of the 11 listings: six of the Chrome Web Store's data categories, web history and website content among them. HARPA AI and OpenAI's ChatGPT search declare none. Every listing carries a privacy section in which the developer states what it handles, and we copied each one on 12 October 2026. These are the developers' own declarations. Google doesn't audit them line by line.
| Extension | Data types the developer declares | Count |
|---|---|---|
| Claude | Personally identifiable information, personal communications, location, web history, user activity, website content | 6 |
| Grammarly | Personally identifiable information, personal communications, location, user activity, website content | 5 |
| Monica | Personally identifiable information, financial and payment information, personal communications, user activity | 4 |
| QuillBot | Personally identifiable information, personal communications, location, website content | 4 |
| Whizi AI | Personally identifiable information, authentication information, personal communications | 3 |
| Sider | Personally identifiable information, website content | 2 |
| Merlin | Personally identifiable information, location | 2 |
| MaxAI | Personally identifiable information, user activity | 2 |
| Glasp | Personally identifiable information, website content | 2 |
| HARPA AI | None: "will not collect or use your data" | 0 |
| ChatGPT search | None: "will not collect or use your data" | 0 |
A short declaration doesn't prove a tool collects less. In August 2025, UCL researchers told the USENIX Security Symposium what ten AI browser assistants actually sent. Merlin captured form inputs, such as online banking and health details. Sider and TinaMind shared users' questions and IP addresses with Google Analytics. Monica, Copilot and ChatGPT for Google guessed users' age, gender, income and interests. Perplexity showed no profiling. Those were 2025 versions, and Merlin's listing today declares only identity and location.
Fakes are the newer risk. In March 2026, Microsoft reported AI assistant extensions with about 900,000 installs that logged ChatGPT and DeepSeek chats and uploaded them to attacker servers. So check that the developer name on a listing is the company you expect.
Any sidebar that answers questions about a page has to send that page somewhere. So switch it off before you open your bank, your medical portal or a work document. The AI chatbot privacy comparison covers what the chat apps behind these extensions keep and train on.
Whizi's Chrome extension loses on page access and on users
Whizi, which publishes this page, has its own extension, and it loses to every sidebar above on what it can do in the browser. The Whizi AI listing is a toolbar popup that chats with one model, Whizi AI, which runs on Claude Haiku. It can't read the page you're on, summarize a video or fill a form, and it had 3 users and one rating on 12 October 2026. What it does do is save every popup chat to your Whizi history, so you can pick it up on whizi.io with 280+ models. A free Whizi account gets 10 messages a day, and each popup message costs 1 credit on a paid plan. If you want the page read for you, install Sider or Claude in Chrome instead.
- Check the rating count, not just the stars: 4.9 from 114,500 ratings means more than 5.0 from one
- Read the privacy section on the listing before you install, and look for "website content" and "web history"
- Check the developer name on the listing, since fake AI assistant extensions reached about 900,000 installs in 2026
- Turn the sidebar off before you open banking, health or work pages
- Try the free plan first, since MaxAI says its payments are final
- Look at the last updated date: ChatGPT search hasn't changed since December 2024
Frequently asked questions
What is the best free AI Chrome extension?
Gemini in Chrome is the best free option if your country has it, because there's nothing to install and Google's help page names no paid plan for it. Among extensions you install, MaxAI's free plan gives unlimited chat on its fast free model plus 3 Pro chats a day, as of October 2026. Monica Free gives 40 basic queries a day, and HARPA's demo gives 10 messages a day. Is Gemini free covers the limits on the free Gemini app.
What is the best AI Chrome extension for students?
Glasp is the best free pick for reading, and Grammarly is the best for writing. Glasp's free plan summarizes 3 YouTube videos a day, takes 30 PDF uploads and gives 20 PDF chat messages a month. Grammarly's free plan gives 100 AI prompts a month, as of October 2026. Claude in Chrome needs a paid Claude plan, so it's the costlier choice for a student. Claude student discount covers what students actually pay for Claude.
Are AI Chrome extensions safe to use?
They're as safe as what they send home, and that varies. A UCL study presented at USENIX Security in August 2025 found Merlin capturing form inputs, and Sider sharing questions and IP addresses with Google Analytics, while Perplexity showed no profiling. In March 2026 Microsoft found fake AI assistant extensions with about 900,000 installs logging ChatGPT and DeepSeek chats. Read the privacy section and developer name on each listing, and switch sidebars off on sensitive pages. Is a third party AI subscription safe lists checks to run on any vendor.
Does Gemini in Chrome need an extension?
No. Gemini in Chrome is built into the browser on Mac, Windows and Chromebook Plus. Google's help page says you have to be signed in to Chrome, be 13 or older, use a supported language and live in a supported region. Its auto browse agent is a preview for Google AI Pro and Ultra subscribers in the US, as of October 2026. Is Google AI Pro worth it weighs that plan against ChatGPT Plus and Claude Pro.
