Best AI Browser Extensions for Productivity (2026): 8 Picks and a Safety Checklist

The best AI browser extension for productivity in 2026 is Claude in Chrome, if you already pay for Claude. It's the one on this list that can actually do work for you: click through a vendor portal, fill in a form, pull numbers from three tabs into one summary. If you don't pay for Claude, start with Gemini in Chrome, which is built into Chrome, costs nothing, and handles the everyday "summarize this page" and "what does this clause mean" jobs without installing a third-party extension at all.

Everything else is a specialist. Merlin, Sider and Monica are multi-model sidebars. HARPA AI is for automation nerds. Grammarly fixes your writing wherever you type, and Readwise Reader is for people who read a lot and want to keep what they read.

But read the security section before you install anything. AI extensions ask for some of the broadest permissions a browser can grant, and the last two years have produced real, well-documented cases of AI-branded extensions stealing chats and session cookies.

Quick picks

• Best overall (paid): Claude in Chrome, for handing off multi-step web tasks.
• Best free option: Gemini in Chrome. Nothing extra to install.
• Best multi-model sidebar: Sider, with Merlin a close second.
• Best for automation: HARPA AI.
• Best for writing everywhere: Grammarly.
• Best for reading and research: Readwise Reader.

Our pick

C

Claude in Chrome

4.5

Best for: Handing off multi-step web tasks to an AI agent · Included with any paid Claude plan; no free access

Claude in Chrome is our pick. Since August 2026 it's been generally available on every paid Claude plan, and it's the most capable option here for tasks that span several pages and several clicks. It also has the most detailed public safety story of any agent in this roundup.

On a budget? Use Gemini in Chrome for free summaries and questions about the page you're on, and add Grammarly Free if you write a lot.

Try Claude in Chrome(opens in a new tab)

How the extensions compare

AI browser extensions at a glance (September 2026)

Feature	WinnerCClaude in Chrome	GGemini in Chrome	MMerlin	SSider	MMonica	HHARPA AI	GGrammarly	RReadwise Reader
Our rating	4.5	4.3	3.9	3.9	3.7	4.0	4.5	4.2
Pricing	Included with any paid Claude plan; no free access	Free built-in; auto browse needs Google AI Pro or Ultra	Free with daily limits; Pro $19/mo billed annually	Free with daily credits; paid Basic, Plus and Ultra tiers	Free with limits; paid Pro, Max and Ultra tiers	Free demo; $12/mo billed annually; $240 lifetime	Free; Pro $12/mo billed annually ($30 monthly)	30-day trial; $9.99/mo billed annually
Best for	Handing off multi-step web tasks to an AI agent	Free page summaries and Q&A without installing anything	One sidebar with many AI models, plus YouTube and page summaries	Comparing answers from several models side by side	An all-in-one sidebar for chat, translation and quick writing	Repeatable web automations, page monitoring and data extraction	Real-time writing fixes in every text box	Saving, highlighting and questioning long articles with AI
Free tier	No	Yes	Yes	Yes	Yes	Demo only	Yes	30-day trial
Main job	Browser agent	Page Q&A, agent on paid plans	Multi-model sidebar	Multi-model sidebar	Multi-model sidebar	Automation commands	Writing fixes	Read-it-later with AI
Chrome Web Store users	Not checked	Built into Chrome	900,000	5 million	3 million	400,000+	Not checked	Not checked

User counts are what each extension's Chrome Web Store page showed on September 28, 2026. Treat them as a popularity signal, not a safety signal. We'll explain why below.

A note on "clicks and fills forms": Gemini's agent mode, auto browse, is limited to paying Google AI Pro and Ultra subscribers. Monica and HARPA advertise agent and automation features, but they're less sophisticated than Claude's or Gemini's agents, and they don't document their prompt-injection defenses in anything like the same detail.

The picks, one by one

Claude in Chrome

C

Claude in Chrome Our pick

4.5

Visit Claude in Chrome(opens in a new tab)

Pricing

Included with any paid Claude plan; no free access

Best for

Handing off multi-step web tasks to an AI agent

Claude in Chrome turns Claude into an agent that reads pages, types, clicks links, moves between tabs and fills out forms. Per Anthropic's product page, it can run tasks in the background, and it works on internal dashboards and legacy systems that have no API. It uses the logins you already have in Chrome.

A few things to know as of September 2026. It needs a paid Claude plan, and Anthropic says it doesn't run on other Chromium browsers or on mobile yet. So Edge, Brave and Arc users are out. By default it now approves actions it judges safe automatically, with a classifier checking each one against your request. You can switch to a permissions mode where you approve sites yourself, and it stops before sensitive actions like purchases.

Anthropic's own evaluations report very low prompt-injection success rates for its newest models with all safeguards on, and much higher rates for older models (16.7% for Opus 4.5). That's encouraging, and it's also a vendor measuring itself. Anthropic's product page still advises against using it on banking, health records or credential-heavy workflows. We'd follow that advice.

Good tasks to hand it: collecting prices from several supplier sites into a table, pulling this month's figures out of a clunky admin panel, drafting replies in a web app you use daily. If you're undecided between assistants in the first place, our ChatGPT vs Claude vs Gemini comparison covers the chat side.

Gemini in Chrome

G

Gemini in Chrome

4.3

Visit Gemini in Chrome(opens in a new tab)

Pricing

Free built-in; auto browse needs Google AI Pro or Ultra

Best for

Free page summaries and Q&A without installing anything

Gemini in Chrome isn't an extension you install. It's a side panel built into Chrome that can summarize articles, explain what's on the page, draft text and talk to Google apps like Gmail, Calendar and Maps. Google's January 2026 update added auto browse, an agent that handles multi-step chores, but only for AI Pro and Ultra subscribers in the US at launch.

The side panel itself is free. Google expanded it to Canada, India and New Zealand in March 2026, then to Latin America, Africa, the Middle East and more in June, on Windows, macOS and ChromeOS. Google says it's available on all Workspace plans too, which makes it the easiest AI assistant to roll out at work. Availability still varies by country, so check whether the Gemini icon shows up in your Chrome toolbar.

Why it ranks so high: it's the lowest-risk way to get AI in your browser. You're not granting a small third-party developer access to every page you visit. Google already makes the browser.

Merlin

M

Merlin

3.9

Visit Merlin(opens in a new tab)

Pricing

Free with daily limits; Pro $19/mo billed annually

Best for

One sidebar with many AI models, plus YouTube and page summaries

Merlin, from Foyer Tech, is a sidebar that puts models from OpenAI, Anthropic, Google and others behind one shortcut (Ctrl+M or Cmd+M). It summarizes pages and YouTube videos, chats with PDFs, drafts Gmail replies and translates. Its Chrome Web Store listing showed 900,000 users and a Featured badge in September 2026.

Merlin's pricing page lists Pro at $19 a month billed annually, and there's a free tier with a daily query allowance. The appeal is simple: one subscription instead of paying OpenAI, Anthropic and Google separately. The catch with every aggregator is that "unlimited" plans have fair-use caps, and you're trusting a middleman with everything you send to all those models.

Sider

S

Sider

3.9

Visit Sider(opens in a new tab)

Pricing

Free with daily credits; paid Basic, Plus and Ultra tiers

Best for

Comparing answers from several models side by side

Sider is the most popular multi-model sidebar we looked at, with 5 million users on its Chrome Web Store listing. It lets you chat with GPT, Claude, Gemini, DeepSeek and Grok models, compare their answers side by side, and work with PDFs, images and YouTube videos. It also runs on Edge, Safari, iOS and Android.

Side-by-side comparison is Sider's best trick. Ask a tricky research question and you can see where the models agree and where one goes off the rails. Sider recently simplified its plans for new customers to Basic, Plus and Ultra, all drawing on a single credit pool. The free plan uses a small daily credit allowance. Check the pricing page for current amounts, since the credit system has changed more than once.

Monica

M

Monica

3.7

Visit Monica(opens in a new tab)

Pricing

Free with limits; paid Pro, Max and Ultra tiers

Best for

An all-in-one sidebar for chat, translation and quick writing

Monica, published by Butterfly Effect Pte. Ltd., is an all-in-one sidebar with multi-model chat, page and PDF summaries, translation, Gmail reply suggestions, image generation and a "memo" knowledge base. Its store listing showed 3 million users in September 2026.

Monica does a bit of everything, which is both the pitch and the problem. If you want one extension for chat, translation and quick rewrites, it's pleasant. If you care about one of those jobs, a dedicated tool does it better. Monica offers free, Pro, Max and Ultra plans. Its pricing page wouldn't load for us, so check monica.im/pricing for current prices.

HARPA AI

H

HARPA AI

4.0

Visit HARPA AI(opens in a new tab)

Pricing

Free demo; $12/mo billed annually; $240 lifetime

Best for

Repeatable web automations, page monitoring and data extraction

HARPA AI, from a Finnish company, is built for automation. It ships with 100-plus commands to summarize, extract data to CSV or JSON, monitor prices and page changes, and chain steps together. It can use cloud models or connect to your own ChatGPT, Claude or Gemini web sessions.

Per HARPA's pricing page, the free demo is limited to 10 messages a day on web connections. Paid plans are $12 a month or $19 a month billed annually (the pricier one adds scheduled commands and advanced automation), or $240 once for lifetime access. HARPA says it keeps your data locally. It's the tool for someone who wants "check this competitor page every Monday and tell me what changed," not for casual chatting. Its learning curve is real.

Grammarly

G

Grammarly

4.5

Visit Grammarly(opens in a new tab)

Pricing

Free; Pro $12/mo billed annually ($30 monthly)

Best for

Real-time writing fixes in every text box

Grammarly is still the best AI extension for fixing writing as you type, in Gmail, LinkedIn, Slack, Google Docs and almost any text box. Free covers grammar, spelling and tone. Pro is $12 a month billed annually.

We won't repeat the full breakdown here. Our Grammarly vs QuillBot comparison covers plans, AI prompts and privacy settings. One tip: turn off the AI training toggle in your account settings if you type client work into it.

Readwise Reader

R

Readwise Reader

4.2

Visit Readwise Reader(opens in a new tab)

Pricing

30-day trial; $9.99/mo billed annually

Best for

Saving, highlighting and questioning long articles with AI

Readwise Reader is a read-it-later app with a browser extension that saves articles, lets you highlight on any page, and includes an AI assistant, Ghostreader, for defining terms, summarizing and asking questions about what you're reading. It's included in the Readwise Full plan.

According to Readwise's pricing page, Full costs $9.99 a month billed annually after a 30-day free trial, with 50% off for students. It's the pick for researchers, writers and anyone who wants AI to help them understand long reads rather than skip them. For one-off long documents, our guide to summarizing long PDFs with AI for free may be enough.

What about the Perplexity extension?

Perplexity's Chrome extension still exists, but when we checked, its store listing showed a last update in October 2023. Perplexity's energy has clearly moved to its own browser, Comet. If you like Perplexity for research (see our Perplexity review), Comet or the Perplexity website is a better bet than the old extension.

AI browsers as an alternative

Some people skip extensions and switch browsers. Here's where the main AI browsers stand in September 2026:

• Comet (Perplexity). Perplexity made Comet free for everyone in October 2025, after launching it for top-tier subscribers. It has an assistant for search, summaries and tab tasks built in.
• ChatGPT Atlas (OpenAI). Atlas launched on macOS in October 2025 and shut down on August 9, 2026. OpenAI moved its browser-agent features into the ChatGPT desktop app. If you relied on Atlas, that's where to look now.
• Dia (The Browser Company, now owned by Atlassian). Dia is an AI-first Chromium browser that's still Mac-only (Apple Silicon) according to recent reporting, and Atlassian has been pitching it at work use.

Switching browsers means moving bookmarks, passwords and habits. For most people, adding Gemini or Claude to the Chrome they already use is less disruptive, and the security trade-offs below apply equally to AI browsers.

The security part you shouldn't skip

AI extensions need to see pages to be useful. That means most of them ask for Chrome's broadest permission, which shows up at install time as "Read and change all your data on all websites". That covers your webmail, your bank's site, your company's internal tools, all of it. You're trusting the developer, and anyone who ever gets hold of their developer account.

This isn't hypothetical. Three well-documented cases:

Fake AI sidebars stealing chats. In December 2025, OX Security found two extensions posing as a legitimate AI sidebar that sent users' full ChatGPT and DeepSeek conversations, plus their open tab URLs, to attacker servers every 30 minutes. One had more than 600,000 users and Google's Featured badge. Together they reached about 900,000 people. A big user count and a badge didn't protect anyone.

Hijacked updates to legitimate extensions. On December 25, 2024, attackers phished a Cyberhaven employee's Chrome Web Store account and pushed a malicious update that stole cookies and session tokens, with a focus on social media and AI platform accounts. It was part of a wider campaign that compromised at least 36 extensions used by around 2.6 million people, according to RH-ISAC and Sekoia's analysis. An extension can be safe on the day you install it and dangerous after an automatic update.

Prompt injection in agentic browsers. Brave's security team showed in August 2025 that a hidden instruction in a Reddit comment could make Perplexity's Comet, asked only to summarize the page, grab the user's email address and a one-time login code from Gmail and post them back. Brave's follow-up research found nearly invisible text in screenshots could hijack AI browsers too, and called indirect prompt injection a systemic problem for the whole category. OpenAI itself wrote in December 2025 that prompt injection is "unlikely to ever be fully 'solved'".

The takeaway: an agent that can act as you, while logged in as you, can be tricked by text on a page you never looked closely at. Defenses are improving. They aren't perfect.

A checklist for vetting any AI extension

1. Check the publisher, not just the name. Clones copy names and icons. Click through to the developer's website and make sure it matches the real company.
2. Install from the company's own site link. Go to the vendor's homepage and follow its "Add to Chrome" link rather than searching the store.
3. Read the permissions prompt. If a grammar tool or summarizer asks for your browsing history, clipboard or "debugger" access, ask why.
4. Restrict site access. In Chrome's extension details, set "Site access" to "On click" or to specific sites instead of all sites.
5. Look at the update history and privacy policy. A months-old listing with no updates, or a vague policy hosted on a throwaway domain, is a red flag.
6. Keep the count low. Every extension is another developer account that could be phished. Remove what you haven't used in a month.
7. Don't paste secrets. Client contracts, passwords and personal data shouldn't go into any third-party sidebar. At work, ask IT which extensions are approved.
8. Watch for sudden changes. New permission requests, a new owner or odd behavior after an update are reasons to uninstall first and investigate later.

Which should you pick?

Browser extensions are one piece of a bigger toolkit. Our guide to the best AI productivity tools for work covers the rest, from AI meeting note takers to automating your email inbox.

Frequently asked questions

Are AI Chrome extensions safe to use?

Some are, but the risk is real. Most need permission to read and change data on every site you visit. Stick to extensions from well-known companies, check the publisher, limit site access, and don't assume a Featured badge or a high user count means an extension is trustworthy. In December 2025, a malicious fake AI extension with over 600,000 users had exactly that badge.

Is Claude in Chrome free?

No. As of September 2026, Claude in Chrome requires a paid Claude plan (Pro, Max, Team or Enterprise), and it runs only in Google Chrome, not other Chromium browsers or mobile.

Is Gemini in Chrome free?

The Gemini side panel in Chrome is free for eligible users on Windows, macOS and ChromeOS in a growing list of countries. The auto browse agent, which clicks and fills forms for you, requires a Google AI Pro or Ultra subscription.

What's the best free AI browser extension?

For most people, Gemini in Chrome, since it's built in and free. If you want a third-party sidebar with a free tier, Sider and Merlin both have daily allowances, and Grammarly Free is the best free writing helper.