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.

Video Lecture

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 April 2023, 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 April 2023, the most popular engine of the three is Blink.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 Of the mainstream browsers, Firefox is likely to be the least invasive and permits its telemetry to be fully disabled, but the user must change default settings to do so. It is much more difficult (if even possible) to disable the privacy-concerning features of Chrome and Edge. Brave has its own built-in advertising network and cryptocurrency system, which is concerning even though it can (in current versions, at least) be disabled. Thus, all the mainstream Blink-based browsers have some privacy issues.

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, LibreWolf¹⁴ 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,¹⁵ 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.¹⁶ 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,¹⁷ to utilize the Blink engine without some of the privacy concerns present in the mainstream Blink browsers. There can still be some website compatibility issues with this approach, however, as I observed a few of them when testing Falkon (although some of the issues could have more to do with its built-in ad blocker than the QtWebEngine component).

Mobile Browsers

In the mobile space, only two browser engines are truly viable: Blink and WebKit. Mozilla has ported Gecko to Android, but it is technologically behind the desktop equivalent as of early 2023. Of the two viable engines, there is only 1 choice of browser on Apple iOS, 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.¹⁸ 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 Bromite,¹⁹ 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 GrapheneOS²⁰ 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 as of early 2023 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. Furthermore, some popular sites and services might have code in place that makes it difficult to use a non-mainstream browser.

To mitigate the privacy issues that result from incompatible sites, it is a good strategy to use multiple browsers to isolate sites from one another. Each browser should be configured to provide its maximum privacy settings, which includes disabling all forms of local storage. Use the most private browser for general-purpose Web surfing, and then use the less private choices only when required for specific sites and services. This approach can be combined with other privacy enhancement techniques, such as using a VPN service, to improve overall privacy.

References and Further Reading

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.