Reducing tracking across the websites you visit

Ads that seem to follow you from one website to the next usually come from third-party trackers, which are small pieces of code or stored files that many unrelated sites load in the background. When you read a news story, browse a shop and then check a recipe site, the same tracker can recognize your browser each time and build a profile of what you look at. You can reduce this kind of cross-site tracking with a handful of browser and account settings, but you cannot switch it off completely while you use the open web.

The realistic goal is fewer trackers and less detailed profiles, not invisibility. Websites still see your internet address, your device type and the pages you load on their own domain.

How trackers connect your visits

Many websites include content from other companies, such as an advertising network, an analytics service, a social media button or a video embed. When your browser loads that content, it sends a request to the other company's domain, and that request can carry a cookie the company set during an earlier visit. Because the same company appears on hundreds of sites, it can see that one browser returned to each of them. That mechanism is the basis of retargeting, where something you looked at reappears in an ad on a different site.

Cookies set by a domain other than the one in your address bar are called third-party cookies. Browsers have handled them differently over time. Some block them by default, while others leave them on unless you change the setting. Trackers also use other storage methods, and a technique called fingerprinting combines details such as your screen size, language settings and installed fonts into a recognizable pattern. Fingerprinting is harder to control than cookies, which is one reason cookie settings alone do not finish the job.

Browser settings that limit cross-site tracking

Start with the privacy or security section of your browser settings. Most browsers offer a setting that blocks third-party cookies, sometimes labeled as blocking cross-site tracking or as a strict tracking protection mode. Choose the strongest option you are comfortable with. Strict modes can break some sites, such as certain logins, embedded payment forms and comment widgets. If a page stops working, add an exception for that site instead of turning all protection off.

Some browsers and privacy extensions can also send an opt-out preference signal, such as the Global Privacy Control, which asks sites not to sell or share your personal data. Some US state privacy laws require covered businesses to honor that signal as a request to opt out, but it only matters to sites that read it or are covered by those laws, so treat it as a limited tool rather than a safeguard. The older Do Not Track setting is weaker still, since several browsers have removed it and sites widely ignore it. Clearing cookies and site data at intervals is more useful, because it removes identifiers that trackers have stored. Many browsers can clear this data automatically when they close, although that also signs you out of sites you use often.

Tracker-blocking extensions can add protection. Install them only from the browser's official extension store, read the permissions they request and be cautious about any extension that asks to read and change data on every site you visit. That kind of access is powerful, so grant it only to tools you have checked.

Account and device settings that matter

Tracking does not depend only on the browser. Large platforms record activity inside your account, and they may use that information to choose ads on other sites. Many large accounts include an ad personalization page where you can turn off personalized ads, review the interest categories used for targeting or remove topics you do not want. The names of these pages vary, so search your account settings for ads or personalization.

On phones, the operating system usually decides whether apps can follow you across other companies' apps and websites. Check the privacy section of your phone settings for a tracking or advertising permission, and decline it for apps that do not need it. You can also reset the advertising identifier, a number that apps use to tag your device for ad purposes. Resetting it does not stop every method of tracking, but it breaks the link that existing ad profiles rely on.

Some "sign in with" and social buttons load code from the provider even when you do not click them. That code can let the provider see pages you visit, so the convenience has a cost. If you use one of these buttons often, consider whether a separate email login for shopping and newsletters would keep your everyday accounts less connected.

What reduced tracking can and cannot do

Expect some trade-offs. Stronger blocking can change how sites load, and some features may stop working until you allow them. Ads will still appear, but they are more likely to reflect the page you are viewing than your history across sites. Sites can still log your visits within their own domains, and a logged-in account keeps a record of activity that its provider holds no matter what your browser blocks.

Match your effort to the problem you are trying to solve. If ads feel uncomfortably personal, changing ad settings and blocking third-party cookies usually makes the largest difference. If you are worried about what a particular company knows, reading its privacy policy and using any access or deletion request it offers may matter more than any browser setting. Revisit your settings every few months, because software updates can change defaults and add new options.