Google's Chromium browser explained

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 0.03 percent of all those who ran a browser last month.

Computerworld has put Chrome and Chromium — and Microsoft's new Edge, too — 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, Edge and others. 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. Microsoft, for example, started providing serious input into Chromium in 2019 and regularly boasts about how many "commits" its engineers have contributed to Chromium. In October 2020, the Redmond, Wash. company said its commits — changes made to the source code — had reached 3,700.

The browser compiled from the current Chromium source code is called, not surprisingly, Chromium. Chrome and Edge, on the other hand, begin with Chromium but do not end with it. Instead, Google and Microsoft add their own proprietary code to Chromium that build services like the browser's automated update mechanism and features such as its tab user experience (UX), to create the actual Chrome and Edge.

Think of Chromium as an ancestor of Chrome and Edge — and not necessarily a close one — that shares its DNA with the polished browsers.

How does Chromium differ from Chrome?

Chromium is a subset of Chrome and of Edge, since Google and Microsoft bolt on other components and features to the former to craft their wares. Everything in Chromium is in Chrome and in Edge, but not everything in Chrome or Edge is in Chromium.

The obvious differences lie in accompanying services that Google provides — like the automatic update mechanism — or built-in support for technologies such as digital rights management (DRM) components that let Chrome and Edge 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 or Edge. Google says so, in fact. "It may be tremendously buggy," warns the Chromium download page.

Even the least polished of the four "builds" that Google maintains for Chrome and Microsoft for Edge — both label that "Canary" — is substantially more stable than Chromium.

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

Chrome and Edge can send crash reports and usage statistics to Google and Microsoft, while Chromium cannot. In Chrome, that collection and transmission is off by default. (They can be enabled from the browser's settings panel.) In Edge, such data harvesting may be on or off, depending on the operating system. Windows 10 — by far the most-used platform for Edge — has its own settings that are also applied to Edge. Most instances of Windows 10 will have diagnostic data enabled, so Edge reports to Microsoft. On other OSes, such as macOS, collection is off by default, like Chrome, but can be turned on from the preferences pain. (See this explanation for more information.)

Chromium, on the other hand, lacks this data gathering-and-reporting feature entirely.

Where do 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, Linux x64 and Android.

Google Chromium project

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 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 (or Edge) on the same system?

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

This is identical to the way that the various "channels" of Chrome and Edge 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. The same goes for Edge.

Do browsers besides Chrome rely on Chromium?

Not surprisingly, other browsers 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 — let's be nice and call them boutique — while others have been important in years past but have since faded in popularity. 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 on which Chrome and Edge are based. According to analytics vendor Net Applications, Opera had a 0.70% share in October, just half what it controlled a year earlier. Download Opera here for Windows, macOS and Linux.
• 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 October, Vivaldi's share registered as zero, or too small for measurement. Download Vivaldi here for Windows, macOS and Linux.
• Brave. Founded by a former executive of Mozilla — the developer of Firefox — Brave is best known for stripping out all in-page advertisements and replacing them with its own. Brave claims that it splits revenue with users, who receive a form of crypto-backed currency. Those users may, if they feel like it, shunt all or some of their currency to one or more websites. Like Vivaldi, Brave did not register in Net Applications' share measuring. Download Brave here for Windows, macOS and Linux.

Other browsers that leverage Chromium include made-in-China options such as QQ and Qihoo 360 Secure Browser, as well as Epic and Comodo Dragon.

What does Chromium lack that Chrome has?

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

Chrome's and Edge's update service, the in-browser mechanism that automatically refreshes the application whenever a security update or feature upgrade is pushed to users. (Those updates, whether security- or feature-related, ultimately originate with Chromium, of course.) Chromium does not update automatically, so when, say, fixes are issued for flaws, the browser doesn't get them unless the user takes the time to download a newer version.

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 and Microsoft's own engineers, as well as those rooted out by independent security researchers, are regularly patched in Chromium, so it's just as secure (or depending on one's perspective, just as insecure) as Chrome or Edge.

On the micro level, it's unclear when during Chromium's ongoing, unfolding development engineers add security fixes. Chrome's Stable channel is refreshed with patches about every two or three weeks — Edge usually follows suit two days later — so the Chromium browser must be updated at least that frequently. But because bug fixes hit the more unstable channels of Chrome and Edge — 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 because Chromium lacks an update mechanism, any security patches applied to the source code will not be reflected in a user's copy of Chromium unless that 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 have piggybacked malware onto Chromium or distributed 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 — the user or an IT 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 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 the "Canary" channel.

Unlike Chromium, Canary is updated automatically and includes the full suite of Chrome or Edge 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 or Edge's "Stable" channel, the one most users run.

Google

"Get on the bleeding edge of the web. Be warned: Canary can be unstable," Google states on its website. Canary builds of Chrome can be downloaded here.

Microsoft also wards off the cautious from trying Canary. "Want to see what we were working on yesterday? Canary will be released automatically almost every night to keep you up to date on our progress," the company says on its site. Canary builds of Edge can be downloaded here.

Neither Google nor Microsoft offer a Linux Canary. Instead, users can run the "Dev" channel build of Chrome or Edge.

Chromium rules the web waves

Although Chromium — specifically, in Chrome form — has been the world's most popular browser since at least April 2016, Microsoft's abandonment of its own technologies for Edge and the adoption of Google's as their replacement was a major tipping point. January 2020, when Edge returned in Chromium clothes, marked the month when, broadly speaking, only two different browser engines remained: Chromium's Blink and Firefox's Gecko. (Apple's Safari uses WebKit, a predecessor from which Blink was forked.)

There's a distinct possibility that Chromium will be the sole survivor; Firefox has struggled to retain its meager market share — around 7% in October — and its parent company, Mozilla, has been under serious financial stress. If Mozilla goes belly up and Firefox disappears, Chromium will be it on the desktop. (Apple's WebKit-powered Safari has a very small share on personal computers, but a more respectable 17% on mobile.)

Microsoft explained its decision to go Chromium in an announcement almost two years ago. "We're announcing that we intend to adopt the Chromium open-source project in the development of Microsoft Edge on the desktop to create better web compatibility for our customers and less fragmentation of the web for all web developers," said then-executive Joe Belfiore, in a Dec. 6, 2018, blog post.

In other words, Microsoft admitted that Chromium won the war and that it was defecting to the former enemy to be, if not exactly an ally, then a Vichy-esque collaborator.

At this moment, the power of Chromium knows no bounds.