Browser Privacy Settings Guide: Block Trackers & Cookies
What Are Third-Party Cookies and Why Block Them?
Third-party cookies are small data files created by a website different from the one you're visiting—typically an advertising network, analytics provider, or social media platform embedded on the page—that allow those third parties to follow you across multiple websites, essentially tracking your online journey.
Their primary purpose is to log interactions such as pages viewed, ads clicked, or searches performed, so the third party can deliver targeted ads, measure campaign performance, or analyze your behavior across the web. In contrast, first-party cookies support core site functions like staying logged in, saving preferences, and keeping items in your shopping cart.
Blocking third-party cookies doesn't break most websites—it simply prevents advertisers and analytics companies from building a profile of your browsing habits across different sites.
Google Chrome: Block Third-Party Cookies
Chrome's approach to tracking privacy has evolved. In 2026, Chrome does not block third-party cookies by default, but instead presents users with a "Privacy Choice" prompt so users decide whether to allow or block them. For maximum privacy control, you should manually enable blocking.
Steps to Block Third-Party Cookies in Chrome
Go to Settings → Privacy and security → Third-party cookies → choose Block third-party cookies. This is the most effective single change you can make for tracking protection in Chrome.
For most people, the best privacy win in Chrome is blocking third-party cookies, tightening site permissions (camera/mic/location/notifications), enabling Safe Browsing, turning on HTTPS-First / Always use secure connections, and reviewing Ad privacy.
Additional Chrome Privacy Steps
Once you've blocked third-party cookies, consider these additional hardening measures:
- Review Site Permissions: In Settings → Privacy and security → Site settings, disable camera, microphone, location, and notifications for all sites unless you specifically need them.
- Enable Secure DNS: For better privacy, use Secure DNS (DoH) alongside blocking third-party cookies and tightening Site settings.
- Clear Cookies on Exit: To automatically clear cookies every time you close Chrome, turn on Clear cookies and site data when you close all windows.
Mozilla Firefox: Enhanced Tracking Protection
Firefox takes a more aggressive privacy stance out of the box. The browser includes Built-in Enhanced Tracking Protection that actively blocks known trackers without requiring as much manual configuration.
Understanding Firefox's Tracking Protection Modes
By default, Firefox blocks social media trackers, cross-site tracking cookies, tracking content in Private Windows only, cryptominers, and fingerprinters in Standard mode. Strict Enhanced Tracking Protection blocks social media trackers, all cross-site cookies, tracking content in all windows, cryptominers, and fingerprinters.
Activating Enhanced Tracking Protection in Firefox
To access Enhanced Tracking Protection settings, click the Firefox menu button and select Settings, then click on the Privacy & Security panel on the left side of the screen. Under Enhanced Tracking Protection, click Advanced settings and select Strict.
Total Cookie Protection
Total Cookie Protection is Firefox's strongest privacy protection, built right into the Firefox browser, which keeps every site's cookies separate so third-party tracking can't easily follow your online activity from page to page, and it runs by default—no extensions or add-ons required.
Total Cookie Protection is enabled by default in Standard mode. When you upgrade to Strict mode, you get additional protections alongside Total Cookie Protection.
Important Note About Website Compatibility
With Total Cookie Protection within Enhanced Tracking Protection enabled, Firefox will block third-party cookies to prevent tracking companies from tracking your browsing from site to site; however, this may cause some websites not to work correctly, which is referred to as site breakage. If you encounter a broken site, you can temporarily disable Enhanced Tracking Protection for that domain only by clicking the shield icon in the address bar.
Apple Safari: Intelligent Tracking Prevention
Safari leads the browser market in privacy by default. Safari continues to pave the way for privacy on the web as the first mainstream browser to fully block third-party cookies by default. Most users benefit from Safari's built-in protections without changing any settings, though you can strengthen protections further.
Safari's Intelligent Tracking Prevention (ITP)
Intelligent Tracking Prevention (ITP) is a crucial privacy feature introduced by Apple in Safari to limit third-party tracking across websites. ITP blocks third-party cookies outright, preventing advertisers from tracking users across different websites without their consent.
Non-cookie storage, such as data stored in Safari's local storage, is also limited by ITP; if the data is not accessed within 7 days, it is deleted, but if the data is accessed within that time, its expiration is extended by another 7 days.
Enabling Additional Safari Protections
On Mac:
Open Safari, click Safari in the top navigation bar, choose Settings, select the Privacy tab, and turn on Prevent cross-site tracking to limit third-party tracking across websites. For a stricter setting, turn on Block all cookies to stop websites from saving new cookies entirely.
On iPhone and iPad:
Open your device's Settings app, scroll down and tap Apps, select Safari, and to reduce tracking, turn on Prevent Cross-Site Tracking. For the strictest protection, scroll to Advanced and toggle on Block All Cookies, though this may break some sites.
Additional Safari Privacy Features
The "Prevent cross-site tracking" setting periodically deletes tracking data from third-party content providers, except for third-party content providers you visit. Safari can also hide your Mac from internet trackers with the "Hide IP address from trackers" option.
Privacy Settings Comparison Across Browsers
| Feature | Chrome | Firefox | Safari |
|---|---|---|---|
| Third-Party Cookie Blocking | User opt-in required | Default (Enhanced Tracking Protection Standard) | Default (Intelligent Tracking Prevention) |
| Fingerprinting Protection | Limited | Included in Standard mode | Included by default |
| Social Media Trackers | Ad privacy controls only | Blocked by default | Blocked by default |
| Strict Mode Available | Manual per-site exceptions | Strict Enhanced Tracking Protection | Block All Cookies option |
| Automatic Cookie Clearing | Optional on exit | Default in some contexts | 7-day auto-clear on tracked domains |
Best Practices for Maximum Privacy
Regardless of which browser you use, follow these principles:
- Start with the defaults: Firefox and Safari provide solid protection out of the box. Chrome requires manual adjustment.
- Block third-party cookies: This is the single most impactful privacy setting across all browsers.
- Tighten site permissions: Disable camera, microphone, location, and notification access unless you need them.
- Use private/incognito mode for sensitive browsing: All three browsers offer private modes that don't store cookies after closing.
- Clear cookies regularly: Set your browser to clear cookies on exit, especially if you use shared devices.
- Expect occasional site breakage: When you enable strict privacy settings, some websites may not function perfectly. You can typically allow specific sites as exceptions.
The Bottom Line
The most effective privacy setup is to block third-party cookies, review site permissions, enable Secure DNS, and keep Safe Browsing turned on, which reduces cross-site tracking, protects against malicious sites, and limits unnecessary data sharing while keeping most websites fully functional. Take 10 minutes now to configure your browser's privacy settings, and you'll significantly reduce the amount of data advertisers can collect about your online behavior.