Browser Security Hardening: Settings and Extensions for Real Privacy

Your Browser Is the Frontline

Every time you open a web browser, you are exposing yourself to trackers, fingerprinting scripts, malicious advertisements, and potential exploits. The default settings on most browsers prioritize convenience over privacy. With a few adjustments, you can dramatically reduce your exposure without sacrificing usability.

This guide covers concrete changes you can make today across the most popular browsers.

Choosing a Browser

Not all browsers are created equal when it comes to privacy:

Firefox offers the best balance of privacy, customizability, and compatibility. Mozilla's Enhanced Tracking Protection blocks known trackers, fingerprinters, and cryptominers by default
Brave is a Chromium-based browser with built-in ad blocking, tracker blocking, and fingerprint randomization. A strong choice for users who want privacy without extensive configuration
Chrome prioritizes integration with Google's ecosystem. Privacy-conscious users will need to adjust many settings and add extensions. Google's business model is advertising, which creates inherent tension with user privacy
Safari provides solid baseline privacy with Intelligent Tracking Prevention and built-in fingerprinting defense, but is limited to Apple devices

Essential Browser Settings

Regardless of which browser you use, adjust these settings:

Disable third-party cookies. Third-party cookies are the primary mechanism for cross-site tracking. Block them entirely. First-party cookies, which keep you logged into sites, will continue to work.

Enable Do Not Track. While many sites ignore this header, some respect it, and it costs nothing to enable.

Disable location sharing by default. Set your browser to ask before any site can access your location. Better yet, deny it globally and grant exceptions only when needed.

Turn off search suggestions and URL predictions. These features send every keystroke in your address bar to your search engine in real time.

Disable autofill for payment methods and addresses. Autofill data can be exfiltrated by malicious scripts on compromised websites. Use a password manager instead.

Set your browser to clear cookies on exit. This prevents long-term tracking while allowing cookies to function during your browsing session. Whitelist specific sites you want to stay logged into.

Disable WebRTC or limit it. WebRTC can leak your real IP address even when using a VPN. Firefox allows you to disable it in about:config. Chromium browsers require an extension.

Recommended Extensions

Keep your extension count minimal. Every extension increases your attack surface and can potentially access your browsing data.

uBlock Origin: The gold standard for content blocking. Blocks ads, trackers, and known malware domains with minimal performance impact. Far superior to Adblock Plus or similar alternatives
HTTPS Everywhere (or built-in HTTPS-only mode): Forces encrypted connections wherever available. Most modern browsers now offer this as a built-in setting
Privacy Badger: Developed by the Electronic Frontier Foundation, it learns to block trackers based on behavior rather than static lists
Cookie AutoDelete: Automatically removes cookies from closed tabs while preserving cookies for sites you trust
Skip Redirect: Bypasses tracking redirects that many sites use to monitor which links you click

Extensions to Avoid

Some popular extensions are privacy liabilities:

Free VPN extensions often inject ads, sell your browsing data, or contain malware
Anti-virus browser extensions frequently collect extensive browsing data and provide minimal actual protection
Coupon and deal finders track every page you visit to function
Any extension requesting access to "all sites" without a clear technical reason

Advanced Hardening

For users who want stronger protection:

Firefox about:config tweaks:

Set privacy.resistFingerprinting to true to resist browser fingerprinting
Set network.http.sendRefererHeader to 0 to stop sending referrer headers
Set media.peerconnection.enabled to false to disable WebRTC

Use multiple browser profiles or containers. Firefox's Multi-Account Containers let you isolate different activities. Keep banking in one container, social media in another, and general browsing in a third. This prevents cross-site tracking between contexts.

Consider DNS-over-HTTPS. Configure your browser to use a privacy-respecting DNS provider like Cloudflare (1.1.1.1) or NextDNS over HTTPS, preventing your ISP from seeing your DNS queries.

What Browser Hardening Cannot Do

Even a perfectly configured browser does not protect you from entering your password on a phishing site, from credentials exposed in data breaches, or from malware delivered through files you download and execute. Browser security is one layer of defense, not a complete solution.

Check LeakedSource to verify your credentials have not already been compromised in a breach, because browser privacy means little if your passwords are already in the hands of attackers.