Choosing a Web Browser
An important step in mitigating privacy threats is to make an informed choice about the Web browser(s) that we use. In practice, establishing a privacy-oriented approach to the World Wide Web that is broadly compatible with different websites requires using multiple browsers for different tasks.
Choosing the Platform and Operating Environment
When considering the selection of a private browser, it is first important to realize that if the platform and operating environment are full of telemetry and tracking code, then there is no real way to have privacy on that platform. Choosing a private browser devolves into an academic exercise if the underlying system is leaking away user secrets anyway. The two popular commercial desktop operating environments have been implicated in telemetry and tracking. Windows 11 has been found to transmit quite a bit of data back to Microsoft,1 while macOS is known to report at least every launched application back to Apple.2 Mobile platforms are even worse, since they explicitly support advertising identifiers for the intended purpose of tracking users outright.
For browser privacy to make any sense, it is first necessary to run an operating environment without telemetry and data collection. As of early 2025, the only practical choice is to run Linux, and even then, it is necessary to read distribution reviews and documentation carefully to be sure the vendor has not entered into any commercial partnerships that might involve tracking. Although they are powered by a Linux kernel, Android and ChromeOS are both products of a tracking company, so they cannot be considered equivalent to a fully open-source Linux distribution. While the various BSD distributions (FreeBSD, NetBSD, OpenBSD, etc.) should provide equivalent privacy to a Linux distribution, driver support is lacking for common desktop and laptop hardware.
Browser Engines
Recall that there are 3 major browser engines: Blink,3 Gecko,4 and WebKit.5 There are also corresponding JavaScript engines, but for the purposes of discussing browser choices, we can use the names of the layout and rendering engines to describe the options. For website compatibility purposes, the choice of engine will have the greatest impact, since Web designers often primarily test their products with a single engine. As of February 2025, the most popular engine of the three is Blink, since Google Chrome still has 66% of the market share. Webkit is in second place, with Safari holding about 18% of the market. Gecko is in a distant third place, since Firefox only occupies about 2.5% of the market.6
Browsers that utilize the Blink engine include two of the most proprietary choices: Google Chrome7 and Microsoft Edge.8 The Brave9 browser also uses Blink, as do some others. Among the less popular engines, Firefox10 and its rebuilds use Gecko. On macOS and iOS systems, Safari11 uses WebKit.
Mainstream Browsers
A major difficulty with all the mainstream browsers – that is, Chrome, Edge, Brave, Firefox, and Safari – is that they all contain telemetry.12,13 Chrome and Edge are, by far, the worst browsers for individual privacy. In 2024, Google deleted personal records that it quietly collected from over 136 million people to settle a lawsuit after it was discovered that Chrome was collecting all website addresses visited in Incognito mode.14 Edge has been found to report the same information to Microsoft.12 Brave contains its own STAR telemetry system, and it also has a built-in advertising network and cryptocurrency system.16 While these “features” can be disabled in the current version of Brave, the mere presence of these technologies is concerning, since a future update could enable them by default or make them impossible to disable.
Although telemetry can be turned off in Firefox, recent developments at Mozilla raise concerns about long-term privacy implications of this browser. In 2024, Mozilla acquired an advertising technology company17 and then pushed out a Firefox update that enables built-in ad measurement within the browser.18 Later in the same year, the company laid off is advocacy division, which was the unit of the company that championed privacy and open Internet standards.19 In early 2025, Mozilla added a Terms of Use statement to Firefox, which originally appeared to give the company the right to harvest user data to train Artificial Intelligence (AI) models. After a public outcry, these terms were slightly rewritten.20
Community Rebuilds
One way to mitigate the privacy issues in the mainstream browsers is to find a community rebuild that is created from the corresponding browser’s source code. These community rebuilds can have telemetry and tracking features removed or disabled by default, making them potentially viable alternate browser choices. There is one downside with these options, which is that the stricter privacy settings might not be compatible with all websites. For a Gecko-based browser, LibreWolf21 is a community rebuild of Firefox that has telemetry disabled and adopts stricter default privacy settings. One option for a Blink-based browser is ungoogled-chromium,22 which has Google’s integrations removed where possible and otherwise disabled where they are not easily removed.
Another way to gain access to the Blink engine is to use a browser based on QtWebEngine.23 QtWebEngine is a browser control for the Qt windowing toolkit, which is used by several desktop environments on Linux systems (such as KDE Plasma and LXQt). To create the QtWebEngine component, the Qt developers take the Chromium source code and remove the various Google integrations. It is then possible for a browser based on this toolkit, such as Falkon,24 to utilize the Blink engine without some of the privacy concerns present in the mainstream Blink browsers. Recent versions of QtWebEngine and Falkon appear to have resolved some site compatibility issues that I previously observed in prior testing.
Mobile Browsers
All three browser engines are available on smartphones and tablets, although Blink and WebKit also dominate this sector. Mozilla has ported Gecko to Android and has recently improved its feature set. However, Firefox for Android still contains some proprietary code and tracking capabilities, some of which are removed by the third party Fennec F-Droid rebuild.25 There is currently only 1 choice of browser engine on non-jailbroken Apple iOS devices, and that is essentially Safari in the form of iOS WebKit. App Store guidelines require that no other browser components or engines can be included in iOS apps.26 Government regulations and/or court decisions could change this situation in the future.
On Android devices, there are more choices of browser, but privacy is still not on par with desktop browsers. One example of such a browser is Cromite,27 which is a Chromium rebuild that has some added privacy features. However, it is important to remember that the browser can only be as private as the platform allows. Unless special care is taken to use a hardened environment like GrapheneOS28 without Google Play Services, Android should not be regarded as a private platform. Even with platform hardening in place, there can still be information leaks from device and cellular modem firmware due to the nature of mobile devices.
Using Multiple Browsers
The best advice I can give for browser privacy is to use multiple browsers on a private desktop platform (such as Linux). Use of mobile browsers should be limited to situations in which a desktop or laptop computer is not available or not practical to use. Since some browser engines will not work properly with some (poorly designed) websites, it is not practical to settle on a single engine or a single browser. Using multiple browsers also makes it easier to isolate sites from one another when using multiple sites or cloud-based services at the same time. Each browser should be configured to provide its maximum privacy settings, which includes disabling all forms of local storage. This approach can be combined with other privacy enhancement techniques, such as using a VPN service with some of the browsers, to improve overall privacy.
In general, the Gecko engine has greater privacy controls and should be used for general-purpose Web surfing. Given the recent issues at Mozilla, an open-source rebuild like LibreWolf21 or the Mullvad Browser29 should be used as the Gecko-based choice. Some websites do not work well with the Gecko engine, so at least one Blink-based browser is also needed. On Linux systems, the Falkon24 browser or Ungoogled Chromium22 can be used. Mac and Windows users may want to use Brave9 as the current least bad choice, although neither platform should be regarded as private.
References and Further Reading
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The PC Security Channel. “Has Windows become Spyware?.” January 29, 2023. ↩
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Jeffrey Paul. “Your Computer Isn’t Yours.” November 12, 2020. ↩
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The Chromium Projects. “Blink (Rendering Engine).” ↩
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MDN Web Docs Glossary. “Definitions of Web-related terms: Gecko.” ↩
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Statcounter Global Stats. “Browser Market Share Worldwide.” ↩
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Mozilla Corporation. “Download Firefox for Desktop.” ↩
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Douglas J. Leith. “Web Browser Privacy: What Do Browsers Say When They Phone Home?.” IEEE Access: 9, 41615-41627. March 10, 2021. ↩↩
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Brave Software. “Privacy-Preserving Product Analytics.” ↩
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Michael Liedtke. “Google will purge billions of files containing personal data in settlement of Chrome privacy case.” AP News. April 1, 2024. ↩
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STAR: Brave’s new system for privacy-preserving data collection. Brave. July 19, 2022. ↩
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Thomas Claburn. “What’s up with Mozilla buying ad firm Anonym? It’s all about ‘privacy-centric advertising’.” The Register. June 18, 2024. ↩
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Pranay Parab. “Firefox’s New ‘Privacy’ Feature Actually Gives Your Data to Advertisers.” Lifehacker. July 16, 2024. ↩
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Gaby Del Valle. “Mozilla is eliminating its advocacy division, which fought for a free and open web.” The Verge. November 5, 2024. ↩
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Sarah Perez. “Mozilla rewrites Firefox’s Terms of Use after user backlash.” TechCrunch. March 3, 2025. ↩
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Qt Wiki. “QtWebEngine.” ↩
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Apple Developer. “App Store Review Guidelines 2.5.6.” ↩