Google's Chromium browser explained

Chrome is the most popular browser in the world, but there would be no Chrome without Chromium, the open source project that underpins it. Here's what Chromium is, where you can download it and how it shapes your online experience. [And, if you hate it, here's how to get rid of it.]

chromium logo blue
The Chromium Development Documentation Project/"The Chromium Authors" (CC BY 2.5)

While the names are similar - Chrome and Chromium - the labels represent two different web browsers. But they are related.

One leads to the other. One is open-source, the other is not, not really. One dominates the world's browser landscape, like a single huskie dominates a team of Chihuahuas on the Iditarod. The other is used by less than one-sixth of one percent of all those who ran a browser last month.

Computerworld put Chrome and Chromium under the magnifying glass to better understand what Chromium does and how it figures into the development of its offspring. Here's what you need to know to better understand them both.

What is the Chromium browser?

Chromium is not only the name of a browser, but also of the open-source project that generates the source code used by Chrome. Google is the primary backer of Chromium - it kicked off the project when it launched Chrome in September 2008 - but because the code is open-source, others, including people not employed by Google, contribute to the Chromium project. (A separate but related open-source project, dubbed Chromium OS, is the foundation for Google's Chrome OS operating system.)

The browser compiled from the current Chromium source code is called not surprisingly, Chromium. Chrome, on the other hand, begins with Chromium but does not end with it. Instead, Google adds proprietary code to Chromium, either its own, like the browser's automated update mechanism, or someone else's, such as Adobe Flash (for now at least), to create Chrome.

Think of Chromium as an ancestor of Chrome - and not necessarily an immediate one, either - which shares the same DNA as the polished browser.

How is Chromium different from Chrome?

Chromium is a subset of Chrome, since Google bolts on other components and features to the former to craft the latter. Everything in Chromium is in Chrome, but not everything in Chrome is in Chromium.

The obvious differences lie in accompanying services Google provides - like the update mechanism - or built-in support for such technologies as Adobe's Flash Player and digital rights management (DRM) components that let Chrome play copyrighted content.

But the biggest difference is not in the length of the two browsers' feature or support lists, but in their inherent stability (or instability). Chromium is rough, and not just around the edges. In practical terms, the latest version of the Chromium browser will be far buggier, much more prone to crashes, than even the rawest version of Chrome. Google says so, in fact. "It may be tremendously buggy," warns the Chromium download page.

Even the least polished of the four "builds" Google maintains for Chrome - the one labeled "Canary" - is substantially more stable than Chromium.

A second difference, and one that many have relied on when they've chosen Chromium over Chrome, is that the former collects and transfers less information to Google than the latter.

Chrome can send crash reports and usage statistics to Google, while Chromium cannot. In Chrome, that collection and transmission is off by default. (They can be enabled from the browser's settings panel.) Chromium, on the other hand, lacks the feature entirely. The information Chrome can collect ranges from where users click to the device's operating system.

Where can I download Chromium?

The most convenient place to get a copy of Chromium is from this download page.

That page should automatically recognize which operating system you're running and offer the appropriate edition of Chromium. If it doesn't, select from the list at the bottom of the page: Windows x86, Windows x64, Mac, Linux x86 and Linux x64.

The site also identifies the current build number, and its age, with the latter usually in minutes. (That's how fast a version of Chromium turns over.) For Windows and Linux editions, users can also click on the "Last Known Good Revision" link near the bottom of the page to retrieve Chromium from about a year prior.

download chromium Google Chromium project

The Chromium browser can be downloaded like other browers.

For more information about downloading Chromium, including how to find and get a specific version of the browser - to use for testing and debugging, for example - refer to this page on the project's website.

Can I run Chromium and Chrome on the same system?

Chromium can be run at the same time, and on the same system, as Chrome. There is no need to, say, uninstall Chrome to add Chromium to the machine.

This is identical to the way Chrome's various "channels" work on a single Windows PC. (One can, for example, run the "Canary" build of Chrome for Windows alongside the "Stable" version of the browser.)

Do browsers besides Chrome rely on Chromium?

Not surprisingly, browsers other than Google's Chrome have hitched a ride on Chromium's coattails, using the open-source project's source code to bootstrap themselves into an application without all the messy work of building the foundational functionality.

Many are niche, some are boutique, others are, and have been, essential to the browser landscape. They include:

  • Opera. The former Norwegian browser - now owned by a Chinese collective - dropped its proprietary Presto rendering engine in 2013 for Blink, the Chromium-created engine Chrome is also based upon. According to analytics vendor Net Applications, Opera has the largest user share of any non-Google, Chromium-based browser, with 1.6% in January. Download Opera for Windows, macOS and Linux from here.
  • Yandex. Launched in 2012 to, as much as anything, stem the losses to Google of the same-named search firm, this Russian-based browser also relies on Blink, and thus Chromium. Yandex accounted for 0.6% of user share in January. You can download Yandex for Windows and macOS here.
  • Vivaldi. Built by a team largely composed of former Opera engineers, Vivaldi debuted in 2016 and was billed by its CEO as a "throwback" to days when browsers didn't sport minimalistic user interfaces (UIs). In January, Vivaldi's user share was 0.08% (that's eight-hundredths of a percent, or 8 out of every 10,000). Download Vivaldi for Windows, macOS and Linux from here.

What does Chromium lack that Chrome has?

Among the familiar Chrome features and functionality missing from the Chromium browser are:

Chrome's Google Update, the update service and in-browser mechanism that automatically refreshes the application whenever a security update or feature upgrade is pushed to users. Chromium does not update automatically, so when, say, Google's engineers issue security patches, the browser doesn't get them unless the user takes the time to download a newer version.

Adobe Flash Player, which is baked into Chrome, and automatically updates within the browser. Chromium users may manually install the Flash plug-in from Adobe's website, just as they do for, say, Mozilla's Firefox or Apple's Safari, but they must refresh it using Flash's own update service.

Support for the Widevine digital rights management (DRM) module.Chromium can thus not play Netflix content, as that service relies on Widevine to stymie content copying.

Are there security issues with Chromium?

Vulnerabilities found by Google's own engineers or independent security researchers are regularly patched in Chromium - again, the root of Chrome - so the former is just as secure (or depending on one's perspective, just as insecure) as Chrome.

On the micro level, it's unclear when during Chromium's ongoing, unfolding development that engineers add security fixes. Chrome's Stable channel is refreshed with patches about every two or three weeks, so the Chromium browser must be updated at least that frequently. But because bug fixes hit the more unstable channels of Chrome - like the flakiest build, "Canary" - before they do Stable, it follows that the source code maintained by the Chromium Project, and thus the Chromium browser, must be altered before being spun out into "Canary."

But Chromium lacks an update mechanism, meaning that any security patches applied to the source code will not be reflected in a user's copy of Chromium unless the user manually downloads a later version. The omission of an update service is the single greatest security threat to Chromium.

More explicit, and the reason this question regularly comes up, is the fact that criminals piggyback malware onto Chromium or distribute modified versions of the browser to include attack code. (For more, see below.)

How do I get rid of Chromium?

If the browser is legitimate - in other words, the user or a company administrator installed it (though it's doubtful the latter would do so) - Chromium can be removed the same way any application is dumped.

In Windows 10, for example, type uninstall into the desktop search field, then when "Add or remove programs" pops up in the results, select that. Click on the Chromium entry, click the Uninstall button, and in the ensuing dialog box, confirm the action by clicking the Uninstall button there.

On macOS, select the Applications folder in the Finder, locate and right-click Chromium, and choose "Move to Trash."

The chore becomes more involved if Chromium represents malware or a purposefully-infected browser. Criminals have hijacked the browser's name to disguise their attack code, and in some cases bundled the browser with other malicious software or have used the source code to rig a browser so that it floods screens with pop-up ads and steals site credentials. (Bogus Chromiums are almost exclusively found on Windows.)

That final bunch is the most pernicious. They're often part of a larger freeware download, typically but not always found on sketchy websites, and like other unwanted software can be difficult to pry out of a system.

Because of the wide variety of malware that masquerades as Chromium, or accompanies a custom-built version of its source code, no single set of removal instructions will do. Computerworld's best advice: Take a tour through the Internet, searching for "how to remove XX" where XX is the name of the Chromium-based browser refusing to leave. Finally, sic a reputable security package to scan for, and identify the malware, then remove it in its entirety. If the security software doesn't delete the Chromium knock-off browser as part of its scrubbing, uninstall it manually using "Add or remove programs."

What are the alternatives to Chromium?

For those who want an early look at the results of the Chromium Project, but don't care to live dangerously by running a possibly-unstable browser, the best alternative for Windows or macOS is Chrome's "Canary" channel.

google chrome download Google

Google's canary browser is more stable alternative to Chromium.

Unlike Chromium, Canary is updated automatically and includes the full suite of Chrome features and ancillary services, such as device-to-device browser synchronization. Like Chromium, Canary is frequently refreshed - each workday - so it represents a look into the future of Chrome's "Stable" channel, the one most users subscribe to.

"Canary builds are the bleeding edge. Released daily, this build has not been tested or used, it's released as soon as it's built," Google states on its website. Canary builds of Chrome can be downloaded from here.

Google does not offer a Linux Canary. Instead, users can run the "Dev" channel build of Chrome. That, too, can be grabbed from Google's site.

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