AI Browser Extensions: Check Permissions First

AI browser extensions promise to summarise a page, rewrite an e-mail or answer questions about whatever is on your screen. They are convenient, and they also sit in the most sensitive place on your computer: inside the browser, next to your mail, your bank, your documents and your company tools. Before you install one, it is worth spending five minutes on what it can see and what it can do.

This guide explains how AI browser extensions work, which permissions matter, how to vet a publisher, how to limit access and when a plain web app is the safer choice. The advice applies to any extension, whichever assistant it connects to, and it is written for people who are not security specialists.

What AI browser extensions actually do

A browser extension is a small program that runs inside your browser and can change how pages look or behave. AI extensions usually add a side panel, a button on selected text or an overlay on e-mail and document pages. To be useful, they read the content of the page you are on, send some or all of it to a server for processing and show the result.

That last step is the privacy question. The text you select, and sometimes the whole page, travels to the extension’s server and often on to an AI provider. What happens after that depends on the publisher’s policy, which may differ from the policy of the assistant behind it. A tool that looks like a simple helper can therefore create a new data flow that your organisation has never reviewed.

Extension type	Typical access	Main risk
Summariser for the current page	Reads the active page when you click	Page content leaves your device
Writing helper in e-mail and forms	Reads and edits text fields on many sites	Drafts, names and private messages are sent for processing
Always-on sidebar assistant	Reads pages continuously or on every site	Broad collection of browsing content
Meeting or tab recorder	Captures audio, screen or tab content	Recordings of other people, consent and storage
Shopping or coupon helper with AI	Reads product pages and sometimes history	Browsing data used for advertising

The permissions that matter most

When you install an extension, the browser lists what it asks for. Many people click through, and that screen is the best early warning you have. The wording differs between browsers, but a few requests deserve a pause every time.

“Read and change all your data on all websites.” This is the broadest request. It means the extension can read every page you open, including logged-in pages, and modify them.
Access to tabs and browsing history. It reveals which sites you visit and when, even if the extension does not read the content.
Clipboard access. Anything you copy, such as a password or a customer’s address, becomes visible to it.
Cookies and storage. Cookies can include session identifiers that keep you logged in somewhere.
Downloads, file access and screen capture. Useful for some tools, and unnecessary for most summarisers.
Native messaging or running in the background. It allows continuous activity outside the page you are viewing.

The general idea behind a safe choice is the principle of least privilege: a tool should have only the access it needs for its stated job. A button that summarises the page you click on does not need to read every site at all times. If the permissions are wider than the feature, treat that as a reason to look elsewhere.

How to vet the publisher

Permissions tell you what an extension can do. The publisher tells you whether you should trust it with that power. Spend a few minutes on the following checks before you install.

Who is behind it? Look for a named company, a real website, a contact address and a privacy policy written for this product.
How long has it existed? A long history with steady updates is a better sign than a new listing with a flood of identical reviews.
What do the reviews say? Read the critical ones. Complaints about unexpected permissions, ads or changed behaviour are valuable.
Is the privacy policy specific? It should say what is collected, where it goes, how long it is kept and whether it trains models.
Does it match the official service? Many extensions use the name of a well-known assistant without being made by that company. Start from the official website and follow its link to the store.
Who owns it now? Extensions are sometimes sold, and a trusted tool can change behaviour after a new owner takes over.

Our article on AI terms of service red flags lists wording to watch for in the policies you read, and the AI privacy checklist gives twelve questions that work for any vendor, including extension publishers.

Limit what an extension can see

Even a reasonable extension does not need to run everywhere. Browsers let you restrict where it works, and a few settings make a big difference.

Run only when you click. Many browsers offer “on click” or “on specific sites” for extension access. Choose it for anything that reads pages.
Allow only the sites you need. If you use a writing helper in one web mail service, allow it there and nowhere else.
Use a separate browser profile. Keep work, banking and experiments apart, and install AI extensions only in the profile where the risk is acceptable.
Turn it off on sensitive pages. Online banking, health portals, HR systems, admin consoles and password managers should be extension-free zones.
Review installed extensions quarterly. Remove anything you have not used in a month, and check that permissions have not changed after updates.

Also remember what you share by selection. If you highlight a paragraph with a customer’s details and send it to an extension, the details leave your browser. The guide on what not to share with AI lists the categories to keep out, and how to anonymise text before pasting it into AI shows how to replace names and numbers with placeholders.

Work devices and company rules

If you use a work computer, an extension is a business decision, not only a personal one. It can expose customer data, contracts, source code and internal tools to a third party that your company never assessed. Many organisations block extensions by policy or allow only an approved list, and for good reason.

Check your rules before you install anything. If there is no rule, ask your security or IT contact. This is one of the most common forms of shadow AI, meaning AI use that happens outside approved channels, and the article on shadow AI at work explains the risks and how organisations can handle them without banning everything. A company policy such as the one described in how to write an AI use policy should name approved tools and say what to do with the rest.

If you are in a regulated field, such as healthcare, law, finance or education, the stakes are higher. Personal data, client confidentiality and professional duties apply to what you send to any third party, and an extension counts as one.

When a web app is the safer choice

An extension reads the page and your text fields because that is how it works. A web app works differently: you open it in its own tab, paste or type what you choose to share and nothing else leaves your browser. You decide, each time, what the assistant sees. For many tasks this is both safer and easier to explain to a colleague or a customer.

The trade-off is convenience. You switch tabs, copy text and paste the result back. For occasional use that is a small cost for much better control. For heavy daily use you might accept an extension, but only after the checks above, with narrow access and a publisher you can name.

Mio is a web assistant. You open it, choose what to paste or upload and ask your question, so it does not need to read every page you visit, and Mio’s free plan includes Chat and Write modes, which is enough to try this workflow. Chats and files are your own, they are not used to train models and you can export or delete them at any time. If you want help with a page, copy the relevant text, or use a tool designed for that job. The guide to AI live browser versus web page reader explains how reading a page differs from controlling a browser.

Warning signs after you install

Trouble does not always appear at installation. Watch for changes afterwards, because extensions update automatically and can change their behaviour.

New ads, pop-ups or changed search results that you did not expect.
Your home page or search engine changing without your action.
A permissions notice after an update that asks for more access than before.
Slower page loading or unusual battery use that disappears when the extension is off.
Messages from sites about unfamiliar logins or password resets.
Emails you did not write appearing in your sent folder.

If you see any of these, disable the extension, close the browser, remove the extension and change passwords for accounts you used while it was active, starting with e-mail and banking. Turn on two-step verification where it is not on already. For a related threat, see our guide to AI phishing e-mails, because stolen browsing data often feeds more convincing scams.

A five-minute checklist before you install

You do not need to become an expert. A short routine catches most of the problems and takes about as long as reading the store page properly.

Step	Question	Pass if
1	Do I need an extension?	A web app or copy and paste would not do the job
2	Who publishes it?	A named company with a site, contact details and history
3	What does it ask for?	Permissions match the feature and can be limited to chosen sites
4	What does the policy say?	It names what is stored, for how long and whether data trains models
5	Is it allowed here?	Your employer or school permits it for this kind of data
6	Can I remove my data?	There is a clear way to delete your account and content

If a step fails, do not install. If everything passes, install in a separate profile first, restrict site access, and review it again after a month.

Frequently Asked Questions

Are AI browser extensions safe?

Some are, and some are not, so there is no general answer. Safety depends on the publisher, the permissions, the privacy policy and how you configure access. An extension that runs only on chosen sites, from a known company with a specific privacy policy, is far safer than one that reads every page you open.

Which permission is the most risky?

Permission to read and change all your data on all websites is the broadest. It lets an extension see every page you open, including logged-in pages. Clipboard, cookies and browsing history access also deserve caution. Prefer tools that work only when you click and only on sites you select.

Can an extension read my passwords?

An extension with broad page access can potentially see what is typed or displayed on a page, and clipboard access can expose copied passwords. Use a password manager, keep extensions away from login and banking pages and install only tools that you can justify. Never copy secrets into an assistant.

Is it better to use a web app instead?

Often yes. With a web app you choose what to paste or upload, and the assistant sees nothing else. That gives you much better control than an extension that reads pages automatically, and it is how Mio works. The cost is some convenience, because you copy text across tabs. For sensitive work, that trade is usually worth it.

Can my employer see which extensions I use?

On a managed work device, administrators can often list, block or force extensions, and they may log activity under company policy. Treat a work browser as company property and follow the rules. If you are unsure whether a tool is allowed, ask your IT or security contact before you install it.

The Bottom Line

AI browser extensions can be helpful, and they deserve more scrutiny than most apps because they sit inside the browser where your accounts live. Check the permissions, vet the publisher, limit access to chosen sites and prefer a web app when the task is sensitive. To try an assistant that only sees what you paste, start on the free plan and compare options on the Ask Mio pricing page.

AI Browser Extensions: Check Permissions Before You Install