How you are followed
Most tracking runs on third-party cookies, which are small files set not by the site you are visiting but by advertising companies whose code is embedded in it. Because the same few companies sit on millions of pages, they assemble a record of what you read and buy across all of them. When cookies are blocked, trackers turn to fingerprinting, which identifies your browser by its combination of screen size, fonts, time zone and hardware. The plainest method needs no tricks at all: if you stay signed in to a search, video or social account, that company logs what you do under your name.
What private mode does
A private or incognito window discards its history, cookies and form entries when you close it. That is useful on a shared computer, for shopping for a gift, and for seeing prices or search results not shaped by your past. It does not hide your activity from the sites you visit, your internet provider, your employer or your school, and anything you download or bookmark stays.
Settings that do the work
- Set the browser's tracking protection to its strict level and block third-party cookies. If a site breaks, you can relax it for that one site.
- Turn on the option that sends a Global Privacy Control signal, which several states, California among them, require businesses to honor as an opt-out from the sale of your data.
- Add one reputable content blocker, which stops most tracking scripts from loading and makes pages faster.
- Set cookies to clear when the browser closes, with exceptions for the few sites where you want to stay signed in.
- Choose the reject option on cookie banners, which the better-built ones put one click away.
Extensions and profiles
An extension that can read and change data on all websites can see every page you open, including your bank. Extensions with many users are regularly sold to new owners who add tracking or worse. Keep the few you use, check the list twice a year, and remove the rest. A simple habit does as much as any tool: use one browser or profile for accounts tied to your name, and a second one, never signed in to anything, for general reading.
Tip Review the ad settings inside your main search and social accounts as well, and switch off personalization and activity history there. Browser settings cannot touch what those companies record on their own servers.
