The browser: an OS within the OS

Browser overview

Improve Your Personal Digital Security

Browser overview

Blink-based browsers
Gecko-based browsers
WebKit-based browsers
Browsers without rendering engines
Which browser to choose?

Having explored the history and evolution of browsers, we're now going to take a look at the main browsers available today. The choice of browser is not an insignificant one, especially if, as in our case, the priority is security, privacy and digital sovereignty. Each browser has specific advantages, but also weaknesses, often linked to their business model or technical choices.

The aim of this chapter is to help you choose the browser that best fits your needs. I've organized them by rendering engine, but the order doesn't reflect any kind of ranking.

Blink-based browsers

Google Chrome

Chrome benefits from rapid and continuous development, primarily led by Google. It is recognized for its high performance, speed, broad compatibility with modern web standards and a good integration of Google services.

However, from a security and privacy perspective, Chrome raises major concerns. By default, the browser collects a large amount of data on its users (browsing, searches, history...), which is used mainly for advertising purposes by Google. The ability to isolate cookies and trackers is limited by default, and total deactivation of tracking remains complex. Also, even if Chrome is technically secure (effective sandbox, rapid updates...), it remains under the control of a major player whose commercial interests are naturally incompatible with true digital sovereignty.

Another thing to consider is that because of this speed and complexity, Chrome consumes a huge amount of system resources, particularly RAM.

Google Chrome is based on the Chromium project, which is open source. However, Google adds a lot of proprietary code. Therefore it is not considered fully open source.

So I wouldn't recommend using Google Chrome, either personally or professionally (unless, of course, your business depends on the Google suite). In fact, there are some excellent alternatives to Google's services, both local and in the cloud. In particular, I invite you to discover the services offered by Proton :

Proton MailSetting up a secure mailbox

Proton DriveImplementing Backup

Brave

Brave is based on Blink (like Chrome), but differs radically in its privacy-centric approach. By default, Brave blocks ads and trackers, integrates HTTPS Everywhere, and offers advanced protection against fingerprinting and third-party scripts. Its business model is based in part on integrated privacy-friendly advertising, but this remains optional and easily deactivated.

Brave is based on Chromium and all its code is available on GitHub. Only minor parts are partially proprietary. Overall, Brave is very close to an open source browser.

Brave is a powerful alternative to Chrome, combining speed, enhanced security, improved privacy by default and an intuitive Interface. However, I wouldn't necessarily recommend it, simply because it's based on Chromium.

Even though many browsers (including Brave) are based on Chromium while claiming a privacy-oriented approach, an investigation carried out in 2024 revealed the integration, by default, of an API allowing Google to access sensitive information about the user's hardware (CPU, GPU, RAM), as well as his or her activity on Google services. This API, integrated as a non-deactivatable extension in Chrome, was also present in several derivative browsers such as Edge, Opera... and even Brave.

Although Brave has since deactivated this API, this case clearly illustrates the structural dependence of these browsers on Chromium, which remains a project deeply tied to the Google ecosystem. As a result, even privacy-oriented variants of Chromium cannot guarantee total independence or complete protection of user data.

→ "fingerprinting" in the context of internet browsing refers to the set of techniques that involve collecting and analyzing specific and sometimes unique information about your browsing environment, in order to recognize and track you on different websites, without resorting to explicit identifiers such as cookies. This information may include:

Your IP address,
Your Internet service provider,
Your geolocation,
Your browser and its properties,
Your operating system,
Your software version,
Installed fonts,
Your screen resolution and size,
Color depth,
Your time zone and language,
HTML5 canvas,
Graphic rendering analysis,
Your browser extensions,
etc...

To check whether your browser fingerprint makes you unique or if you blend in with the crowd, you can use the following site: https://amiunique.org/

Vivaldi

Vivaldi, founded by the former CEO of Opera, is targeting advanced users looking for a deeper personalization and advanced features such as side panels, an advanced tab manager and integrated note-taking.

In terms of security, Vivaldi includes several features for blocking trackers and ads, but these protections remain slightly weaker than Brave. It is also less transparent in certain respects, as its source code is only partially open source. Nevertheless, it offers an interesting alternative, less focused on strict privacy than Brave, but more so than Chrome or Opera.

Opera

Opera is a Long standing browser, having been around since 1995. It now uses Blink after abandoning its proprietary engine (Presto). It has a modern interface and some innovative features.

However, in terms of privacy, Opera is highly controversial: it has been owned by a Chinese company since 2016, raising questions about the possible exploitation of user data. Opera includes an integrated VPN (proxy rather than a trued VPN), but the privacy policy is unclear about log management. Opera is also a proprietary browser. It is therefore not recommended, especially when privacy is a priority.

Specialized browsers

Blink-based browsers also include a number of more marginal browsers, often designed to meet specific use cases:

Arc:

Developed by The Browser Company, Arc offers a radically different approach to the user interface. It replaces traditional tabs with a system of "spaces", a unified sidebar, and integrates creative tools such as annotatable captures and a simple site editor. The emphasis is on usability, visual customization and fluidity of use, making this a tool favored by some professionals.

From a technical point of view, Arc is based on Chromium, but remains proprietary software. It offers no transparency on data collection, and its privacy policy remains unclear, particularly when it comes to telemetry and synchronization in the cloud. It should therefore be avoided from a digital sovereignty perspective.

Polypane :

Polypane is aimed specifically at front-end developers and UX designers. Its main function is to simultaneously display several instances of the same site on different screen resolutions, in order to test the responsive behavior of an interface in real time. It also offers accessibility tools, HTML/CSS validators, color-blind simulators and performance metrics.

Polypane is a proprietary, paid proprietary browser based on Chromium, which makes it ideal for occasional professional use. It is not suitable for everyday browsing, and its privacy policy is in line with commercial software, with no particular guarantees.

Gecko-based browsers

Mozilla Firefox

Firefox is the most prominent browser using the Gecko rendering engine. Developed by the Mozilla Foundation, Firefox stands out for its clear privacy policy: enhanced tracking protection, advanced options for blocking third-party cookies, isolated tab containers, and integration of security-focused extensions.

Mozilla is a not-for-profit organization, which gives it relative independence from purely commercial interests, even if it remains heavily dependent financially on partnerships with Google. The latter largely funds the Mozilla Foundation, officially so that its search engine remains the default in Firefox, and thus maintains its market share. Unofficially, this strategy enables Google to maintain a form of controlled competition: by supporting Mozilla, Google retains a minimal competitor, which mitigates accusations of abuse of dominant position and limits the risk of regulatory sanctions.

Firefox is an open source browser, distributed under the MPL (Mozilla Public License). Its code is totally free, modifiable and redistributable, and is the subject of numerous external contributions.

Firefox remains a benchmark for security and privacy, despite lagging slightly behind Blink-based browsers in certain performance areas. It can be a very good browser, as long as it is configured properly.

FirefoxHow to configure Firefox to protect your privacy?

Tor Browser

Tor Browser is a browser based on Firefox ESR. It is one of the most robust solutions for online anonymity. It redirects traffic through the Tor network, thus preventing any direct correlation between the user and the web destination.

Tor BrowserHow to use the Tor Browser?

The downside is a significant reduction in performance (high latency) and limited compatibility with certain websites. Tor Browser is ideal for sensitive activities (journalism, activism...), but less suited to ordinary everyday use.

Mullvad Browser

Mullvad Browser is the result of collaboration between the Tor Foundation and Mullvad VPN. It is based on the Tor browser, which is itself derived from Firefox ESR. Mullvad Browser is designed to maximize user privacy. By default, it includes advanced protection against fingerprinting, trackers and third-party scripts.

Mullvad BrowserHow to use the Mullvad Browser for privacy

It has most of the security and privacy features offered by Tor Browser, with one difference: it doesn't redirect traffic via the Tor network. To avoid IP address leaks, you can use it in combination with a VPN (ideally, Mullvad VPN).

Mullvad VPNSetting up a VPN paid for with bitcoins

Mullvad Browser is an excellent solution if you're concerned about your privacy, whether you're a beginner or an advanced user.

Librewolf

LibreWolf is a Firefox-based browser designed to offer an even higher level of privacy. It removes all features that could compromise privacy, such as telemetry, Mozilla services integration and the Pocket service.

By default, LibreWolf activates Firefox's advanced security settings (such as strict tracking protection mode) and disables DRM support. The project is entirely open source, community-based, and does not rely on any funding from private enterprise. I recommend it if you're looking for a "hardened" Firefox, with maximum control over your data.

LibreWolfHow to use the LibreWolf privacy browser

Zen Browser

Zen Browser is a free and open source browser based on Firefox (Gecko engine), launched in 2024. Its aim is to offer a modern, elegant, highly customizable and above all privacy-centric browsing experience, without dependence on Chromium.

Zen stands out for its radical approach to interface and usability, largely inspired by the Arc browser, yet emancipated from it by its open-source nature and Gecko engine. It includes :

A minimalist, modular interface, with a vertical sidebar for tabs, a split view, and a workspace system for grouping sets of tabs by project;
A system of customizable interface templates (Zen Mods) that can be used to deeply modify the browser's appearance;
An original function called Glance, which opens a link in a lightweight temporary window, avoiding the clutter of tabs...

Zen also supports Firefox extensions, as well as synchronization via a Mozilla account.

From a security and privacy point of view, Zen features native blocking of third-party trackers. The browser does not collect any data itself, and it also allows Mozilla telemetry to be disabled. It also automatically rejects obsolete or non-compliant SSL certificates.

Zen Browser is an interesting alternative if you're looking for a Gecko browsing environment that's free, innovative, uncluttered and respectful of your privacy.

Zen BrowserHow to use Zen Browser for productive and confidential browsing?

WebKit-based browsers

Safari

The main browser still using the WebKit rendering engine (not a fork like Blink) is Safari. Safari is Apple's exclusive browser for macOS. It offers excellent integration with the Apple ecosystem, high performance, and now includes stronger protections against tracking and fingerprinting.

However, Safari remains closed, limited to macOS for its desktop version, and dependent on the Apple ecosystem. While Apple has a strong privacy policy, with its business model based primarily on hardware sales rather than advertising, it remains unclear about certain internal practices.

Here, we're focusing on desktop browsers, but it's important to note that on iOS, Apple requires all browsers to use the WebKit rendering engine (a constraint that may soon change, however, as a result of certain European regulations). This means that browsers such as Chrome, Firefox or Brave must, on iOS, offer an application based on WebKit, and not on their usual rendering engine.

Orion

An interesting alternative to Safari is Orion, a modern browser designed exclusively for the Apple ecosystem, and also based on WebKit. Its aim is to offer a fast, lightweight and deeply privacy-respecting alternative, without compromising on advanced features.

Orion differs from Safari in several technical respects:

It adopts a strict zero telemetry policy: no data is collected or transmitted by default, including during initial installation;
It includes an ad and tracker blocker enabled by default, comparable in effectiveness to uBlock Origin in most cases;
It natively supports the installation and use of Chrome and Firefox extensions natively on macOS ;
Useful tools include Focus mode(interface-free navigation), low-power mode and vertical tab management.

Orion is entirely developed by the Kagi team (known for its ad-free search engine). Its development is funded solely by its users via the Orion+ subscription, which gives access to a number of advantages.

Orion BrowserHow to use Orion Browser to protect your privacy on Mac and iPhone?

Browsers without rendering engines

Finally, I'd like to end this overview with a much less known and very marginal alternative: text-mode browsers, the best-known of which is Lynx Browser.

Lynx is the oldest web browser still maintained (1992). It operates exclusively in text mode and is used directly in a terminal, without any graphical interface. Technically, Lynx doesn't support JavaScript, CSS or images, which eliminates any active code execution in web pages. It only interprets raw HTML code, which it renders as structured text.

This radically minimalist approach makes it one of the most secure browsers: no malicious script can run, no intrusive advertising is displayed, and no data leaks via modern mechanisms (canvas fingerprinting, JavaScript trackers, etc) is possible.

This model obviously has major limitations: total absence of graphical rendering, impossibility of using the majority of modern websites (many of which depend on JavaScript) and austere ergonomics intended for experienced users.

Lynx can still be interesting in certain very specific contexts:

Audit raw HTML web pages, without JavaScript or CSS execution;
Browsing in minimalist environments;
Browsing in ultra-secure environments;
Browsing on very slow or unstable networks;
Automation or scraping.

Which browser to choose?

For users who prioritize security and privacy by default, without having to manually modify numerous settings, and who are looking for a general-purpose browser on a daily basis, the best choices in my opinion are LibreWolf and Mullvad Browser. In the same category, if you don't mind using a Chromium base (despite the risks involved and a very different philosophy), you might also consider Brave. As you can see, I prefer the Gecko rendering engine for many reasons, even if it is currently lagging behind Blink in terms of performance.

Firefox is also a very good option as a general-purpose browser, as long as it is properly configured to enhance privacy.

For an even higher level of anonymity, at the cost of reduced performance, Tor Browser remains the best solution.

Chrome, despite its popularity, cannot be recommended as part of a digital sovereignty approach, as Google systematically places its commercial interests above any real protection of privacy. That's why I don't recommend using it.

Today, your choice of browser plays an important role in your online security and privacy. So take the time to identify the one that best suits your risk profile and priorities.

Here's a quick summary to help you make your choice (bear in mind, however, that this comparison may have evolved over time since SCU202 was written, and evaluation of the interface and its features is primarily a matter of personal appreciation):

Browser	Privacy	Speed	Features	Interface	Open source	Resource consumption
Google Chrome	🔴	🟢	🟢	🟢	🔴	🔴
Brave	🟡	🟢	🟢	🟢	🟢	🟡
Vivaldi	🟡	🟢	🟢	🟢	🔴	🟡
Opera	🔴	🟢	🟢	🟢	🔴	🔴
Arc	🔴	🟢	🟢	🟢	🔴	🟡
Polypane	🟡	🟡	🟢	🟡	🔴	🔴
Mozilla Firefox	🟡	🟡	🟢	🟢	🟢	🟡
Tor Browser	🟢	🔴	🟢	🟡	🟢	🔴
Mullvad Browser	🟢	🟡	🟢	🟡	🟢	🟡
Safari	🟡	🟢	🟢	🟢	🔴	🟡
Lynx	🟢	🟢	🔴	🔴	🟢	🟢
LibreWolf	🟢	🟡	🟢	🟡	🟢	🟡
Orion	🟡	🟢	🟢	🟢	🔴	🟢
Zen Browser	🟢	🟡	🟢	🟢	🟢	🟡

In the next chapter, we'll take a look at the best practices for surfing the web safely, while minimizing the exposure of your privacy.

Quiz

scu2024.2

1/5

Which browser guarantees anonymity by redirecting traffic through a decentralized but high-latency network?