What the research really says about how much browser extensions collect, which permissions matter, and why coupon add-ons are the usual suspects.
A browser extension that saves you a few dollars at checkout can also read everything you type on every site you visit, including passwords and card numbers, and most people click “Add” without a second thought. The browser extension privacy statistics that exist paint an uncomfortable picture, though they come with a caveat: no single registry tracks every extension, so the figures come from samples and audits rather than a complete census. Even so, the pattern across studies is consistent enough to act on. Here is what the data shows, and where coupon extensions fit in.
The Short Version
Across audited samples, roughly half of extensions collect some user data, and the large majority of the most popular ones request high-risk permissions on install. The single riskiest permission is the ability to read and change your data on every website. Coupon and shopping extensions are frequent offenders because their whole function relies on that broad access, and the 2024 Honey affiliate controversy showed how that access can be misused. The fix is not to swear off extensions, but to audit what you have installed and remove anything you do not actively use.
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What the studies actually found
Start with the honest limitation: these numbers come from audits of samples, not a full count of every extension, so treat them as strong signals rather than precise universal rates. With that said, the findings line up. In one analysis of 442 extensions summarized by Incogni’s 2026 research, about 52 percent collected at least some user data, with website content collected by 31.4 percent and personally identifiable information by 29.2 percent.
The permission picture is starker. By 2026 analyses, 86 percent of the top 100 Chrome extensions request high-risk permissions at install, and scripting, the ability to run code on pages you visit, showed up in roughly 42 percent of extensions. Transparency is thin too: security researchers have flagged dozens of tools that openly sell user data, and a large share of Chrome Web Store extensions ship with no privacy policy at all. The through-line is that data collection is common and disclosure is rare.
The permissions that should worry you
Not every permission is equal, and one stands above the rest. When an extension asks to “read and change all your data on the websites you visit,” it is requesting exactly what it sounds like: the ability to see and alter everything on every page, which includes the login form you fill in and the bank balance you check. That is the permission to scrutinize hardest.
Scripting and broad host access are the other red flags, because they let an extension inject code into pages and act on your behalf. Some tools genuinely need this to work, a password manager or an ad blocker, for instance. The problem is a coupon widget or a novelty theme asking for the same god-mode access it has no real reason to hold. Match the permission to the purpose, and be suspicious when they do not line up.
Why coupon and shopping extensions are the usual suspects
Coupon and cashback extensions sit at the center of this because their function demands broad access: to find a code at checkout, the extension has to watch what you buy and where. That same access lets it log your browsing and shopping habits, and the incentives do not always favor you. Security teams have found dozens of extensions that inject affiliate codes or harvest data without clear disclosure.
The clearest example is the 2024 Honey controversy, when the popular coupon extension was shown to override other creators’ affiliate links and drew scrutiny over the browsing data it accessed. It was a reminder that a free extension is rarely free: if you are not paying, your data or your clicks are often the product. That is not an argument against all coupon tools, but it is a reason to know what one is doing before you install it.
How to check and cut your risk
You do not need to abandon extensions, just prune and vet them. Open your browser’s extensions page and remove anything you have not used in the last month, since every installed extension is a standing risk even when idle. For the ones you keep, click into their details and read the permissions; if a simple tool wants to read and change all your data, that is a reason to look for a lighter alternative.
Before installing anything new, check the developer, the review count, and whether a privacy policy actually exists, and lean toward well-known tools with a clear reason for the access they request. Some browsers also let you restrict an extension to specific sites or to run only when you click it, which is a good default for anything that does not need constant access. A ten-minute audit removes most of the exposure the statistics describe.
The Bottom Line
The data is not a reason to panic, but it is a reason to pay attention: about half of extensions collect data, most popular ones ask for powerful permissions, and disclosure is the exception rather than the rule. Coupon and shopping add-ons deserve extra caution because broad access is baked into how they work. Audit what you have, remove what you do not use, read permissions before you click Add, and treat “read and change all your data” as the request that has to earn its place. For more on protecting your accounts and data, see YouGottaRead’s guide to spotting scams and locking down your accounts, and browse the Tech section.
Frequently Asked Questions
How many browser extensions collect user data?
In audited samples, roughly half do. One analysis of 442 extensions found about 52 percent collected at least some user data, with website content and personally identifiable information the most common types. These figures come from samples rather than a full census, so treat them as strong signals of a widespread pattern.
What is the most dangerous browser extension permission?
The permission to “read and change all your data on the websites you visit” is the riskiest, because it lets an extension see and alter everything on every page, including login forms and financial pages. Grant it only to tools that genuinely need it, like password managers or ad blockers, and question it everywhere else.
Are coupon extensions safe to use?
Some are fine, but coupon extensions carry more risk than most because their function requires broad access to your browsing and shopping. Several have been flagged for collecting data or injecting affiliate codes without clear disclosure, and the 2024 Honey controversy is the best-known example. Vet the developer and permissions before installing one.
Do browser extensions have to disclose data collection?
Rules are tightening, but disclosure has been inconsistent, and a large share of Chrome Web Store extensions have shipped without a privacy policy. Google has updated its policies to require data minimization and clearer disclosure, though enforcement is ongoing. Do not assume an extension tells you what it collects; check for a policy yourself.
How do I reduce the privacy risk from extensions?
Audit your extensions page and remove anything you have not used recently, read the permissions on the ones you keep, and prefer well-known tools with a clear reason for their access. Where your browser allows it, restrict an extension to specific sites or to run only on click. A short cleanup removes most of the exposure.
