Private browsers compared

A browser can leak a lot: cookies that follow you between sites, a "fingerprint" made from your screen size, fonts and settings, and data the browser itself sends home to its maker. Browsers differ in what they block by default, and defaults matter because most people never change them. This page sets out what each maker says its browser does, plus what independent research has found. Tunnelcheck hasn't run its own browser tests and doesn't give scores.

Three terms you'll need

• Third-party cookie: a cookie set by a company other than the site you're on, often an ad network, which can recognize you across many sites.
• Fingerprinting: identifying your browser from its characteristics, such as fonts, screen size, time zone and graphics behavior, without storing anything on your device.
• Telemetry: usage data the browser sends to its developer. Some is harmless; some carries identifiers that can link your sessions over time.

Default protections at a glance

Tor Browser

Tor Browser sends your traffic through the Tor network, a chain of volunteer-run relays, so the site you visit sees the last relay's address, not yours. Its design aims to make Tor Browser users hard to tell apart; Mullvad Browser, below, reuses that anti-fingerprinting work. The trade-offs are speed and some sites refusing Tor traffic. Once traffic leaves the last relay, called the exit, it's back on the open internet, and the exit can read anything that isn't encrypted, which is why the Tor Project stresses that "plaintext over Tor is still plaintext" and HTTPS still matters (Tor Project blog). For how it compares with a VPN, see VPN vs proxy vs Tor.

Mullvad Browser

Mullvad Browser launched on April 3, 2023. It was built by Tor Project engineers for Mullvad VPN and the Tor Project calls it "Tor Browser without the Tor Network". The idea is to use it with a VPN, or on its own, so you get the anti-fingerprinting design without Tor's slower routing. It's free, open source, and runs on Windows, macOS and Linux (Tor Project, Mullvad). It doesn't need Mullvad VPN. See our Mullvad review for the VPN itself.

Brave

Brave's Shields feature is on by default and, Brave says, blocks third-party ads and trackers including CNAME-cloaked ones, replaces cross-site cookies with temporary storage that's deleted automatically, randomizes or removes browser features used for fingerprinting, and warns about phishing sites (Brave Shields). Brave Software also runs its own ad network, Brave Ads, and a search engine with ads; check the browser's settings to see which ad features are on.

In a study of what browsers send back to their makers, Douglas Leith of Trinity College Dublin found Brave, with default settings, to be the most private of six browsers tested. Chrome, Firefox and Safari came in a middle group, and Edge and Yandex were least private: both sent identifiers linked to the device hardware (IEEE Access, 2021, Sophos). The study measured telemetry only, not tracker blocking, and the browsers have changed since 2020.

Firefox

In June 2022 Mozilla made Total Cookie Protection the default for Firefox users worldwide. It keeps each site's cookies in a separate "jar", so a tracker's cookie on one site can't be read on another (Mozilla blog, Mozilla Support).

LibreWolf

LibreWolf is "a custom version of Firefox, focused on privacy, security and freedom". It removes telemetry and experiments, ships with stricter privacy settings, and includes the uBlock Origin content blocker. It's run by a small volunteer group and says it isn't affiliated with Mozilla (LibreWolf).

Safari

Safari's Intelligent Tracking Prevention is on by default and blocks all third-party cookies, with narrow exceptions (WebKit). Safari 26.0 added a block that stops known fingerprinting scripts from reliably reading device details such as screen size, and from setting long-lived storage (WebKit: Safari 26.0). Apple's stronger Advanced Fingerprinting Protection is on by default in Private Browsing and can be turned on for all browsing in Safari's Advanced settings (WebKit: Private Browsing 2.0). Safari only runs on Apple devices.

What about Chrome?

Google spent years planning to remove third-party cookies from Chrome. In April 2025 it said it would keep its current approach, with cookies allowed by default, and in October 2025 it retired most of its "Privacy Sandbox" replacement technologies (Google Privacy Sandbox). So Chrome still allows cross-site cookies unless you block them in settings. Its Incognito mode doesn't block trackers; EFF notes it offers no tracker protection (EFF Cover Your Tracks).

How to check your own browser

EFF's Cover Your Tracks shows how trackers see your browser, including the characteristics that make up your fingerprint. EFF points out two limits worth knowing. Blockers rely on lists of known trackers, so newer techniques can still get through. And adding unusual settings or extensions can make your browser *more* distinctive (EFF). Tunnelcheck's own browser privacy check and WebRTC leak test cover related leaks.

Which private browser should you use?

• Anonymity from the sites you visit and your network: Tor Browser.
• Tor-style anti-fingerprinting at normal speed, with or without a VPN: Mullvad Browser.
• Strong defaults with Chrome compatibility: Brave.
• Open source, with cookie isolation on by default: Firefox, or LibreWolf if you want the hardening done for you.
• On iPhone, iPad or Mac: Safari's defaults block third-party cookies; turn on Advanced Fingerprinting Protection for all browsing if sites still work for you.

A private browser limits tracking by websites. It doesn't hide your traffic from your internet provider or your Wi-Fi operator. Pair it with a private search engine and, where that matters to you, a VPN.