Chromium (web browser)
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| Developer | The Chromium Projects (Google) |
| First release | September 2, 2008 |
| Written in | C++ (primary), with HTML, CSS, and JavaScript |
| Engines | Blink (rendering), V8 (JavaScript) |
| Platforms | Windows, macOS, Linux, Android, iOS, BSD |
| License | BSD-3-Clause and others |
| Website | chromium.org |
Chromium is a free and open-source web browser project. It is developed mostly by Google, but engineers from many other companies and independent volunteers also contribute to it. Chromium is the foundation that several of the world's most popular browsers are built on, including Google Chrome, Microsoft Edge, and Opera.
The project was first released in 2008, at the same time as Google Chrome. Its goal is to make browsing the web safer, faster, and more stable. Because the code is open, anyone is allowed to read it, change it, and use it to build their own browser. Chromium itself can be downloaded and run as a working browser, but it is mainly meant as a starting point for developers rather than a finished product for everyday users.
1 Overview✎
Chromium is built to feel lightweight and quick. When it first appeared, it introduced several features that many other browsers later copied, such as a sandbox security model that keeps web pages separated from the rest of the computer, a clean and simple interface, and a tabbed window design.
A key idea behind Chromium is its multi-process design. Each tab runs in its own separate process, so if one web page crashes, it does not bring down the whole browser. This design also improves security by isolating pages from one another.
The browser is written mostly in the C++ programming language, which makes up about half of its code. The rest uses HTML, CSS, and JavaScript, mainly for the user interface and for testing.
2 Engines✎
Chromium relies on two main engines that do most of the heavy work.
The Blink engine is the rendering engine. Its job is to turn the HTML, CSS, and other code of a web page into the layout and visuals you see on screen. Blink began in 2013 when Google split off, or "forked," its own version from the older WebKit engine. Today Blink is the most widely used browser engine in the world, largely because so many browsers are based on Chromium.
The V8 engine handles JavaScript and WebAssembly, the code that makes web pages interactive. V8 was created by Google and is known for its fast performance. It is also used outside of browsers, for example in server software.
On Apple's iOS and iPadOS, Chromium-based browsers have historically been required to use Apple's WebKit engine instead of Blink, although Google has been working to bring Blink to those systems.
3 History✎
Chromium and Google Chrome were both first released on September 2, 2008, beginning on Microsoft Windows. Versions for other systems such as Linux, macOS, and Android followed later.
At launch, both browsers used the WebKit engine for rendering web pages. Over time, Chrome's needs for performance and its multi-process design grew apart from WebKit. To meet those needs, Google officially forked WebKit in 2013 to create the Blink engine, which Chromium has used ever since.
A major moment for the project came when Microsoft rebuilt its Edge browser on top of Chromium, releasing the new version in 2020. This meant that two of the most widely used browsers now shared the same underlying technology, making the web more consistent for developers and users alike.
4 Licensing✎
Because parts of Chromium came from the WebKit project, the code uses several different open-source licenses. The portions written by Google are shared under the 3-clause BSD license, which is very permissive. Other parts fall under licenses such as the LGPL, MIT, Ms-PL, and MPL.
This mix of licenses allows almost anyone to take the Chromium code, modify it, and build their own browser from it, which is exactly why so many different browsers exist that are based on Chromium.
5 Browsers based on Chromium✎
Many well-known browsers use Chromium as their base. Because the code is freely available, developers can take it and add their own features, branding, or privacy changes.
Some examples include:
- Google Chrome — Google's own browser, which adds proprietary features on top of Chromium. It is licensed as freeware rather than open source.
- Microsoft Edge — Rebuilt on Chromium in 2020, sharing the same Blink and V8 engines as Chrome.
- Opera — A long-running browser that switched to a Chromium base.
- Brave — A browser focused on privacy and blocking ads and trackers.
- Vivaldi — A highly customizable browser aimed at power users.
- Ungoogled Chromium — A community fork that removes Google's web services for more privacy.
6 Use beyond browsers✎
Chromium's technology is also used in software that is not a traditional web browser. Frameworks built on Chromium let developers create desktop applications using web technologies. Search engine crawlers, such as those used by Google and Bing, also rely on Chromium-based engines to view and understand web pages the way a real browser would.