Chromium is an open-source web browser project that serves as the foundation for several other popular web browsers, including Google Chrome. It was started in 2008, when there was only Internet Explorer and Firefox on the browser market.
It is developed by the Chromium Project which is a community-driven project and is supported by Google.
Chromium forms the basis of Chrome and Edge. Both Google and Microsoft (with Microsoft Edge) have been adding features, enhancements and customizations to their own forks of Chromium. This means that all components in Chromium are included in Chrome and Edge to some degree, but not every feature in Chrome or Edge is available in Chromium.
Other browsers that use parts of Chromium are Opera, Samsung Internet (on Android), Arc browser, Vivaldi, Yandex Browser and Amazon Silk.
Chromium and Selenium Testing
Selenium is a widely used framework for automating web browsers and uses Chromedriver to instrument a Chromium based browser. Usually you would want to test on the browser that your customers are using, which is Chrome.
For that reason, TestingBot only provides Chrome browsers for its visual, manual and automated testing features.
Chromium on Mobile
On Android there is a component called WebView. This is used by Android apps to display web content in a native app. The engine powering this is based on Chromium. This means that testing on Android WebView is equal to testing on Chromium.
Advantages of using Chromium for Testing
While it is true that Chromium lacks some features found in Chrome, some are actually to the advantage of testers. For example, auto-updating is not enabled on Chromium, which means you are sure that you are always testing on the version you want to test on.
Another advantage is the release cycle: Chromium tends to have a more frequent release cycle compared to Chrome. This means you can test on upcoming new features faster than you would be able to with Chrome.
For this reason, TestingBot provides access to beta and development releases of upcoming Chrome browsers. This means you are able to test on upcoming Chrome/Edge browser updates, before these reach the general public.
Playwright uses Chromium
Playwright is a test framework that supports testing on multiple browsers. By default, Playwright will install and use the Chromium browser to run browser tests. The main reason for this is probably because Microsoft is backing Playwright and they do not want to use the Google branded Chrome browser.
The NPM package
playwright-chromium will automatically install the correct Chromium binary, depending on the OS and Playwright version you are using.
When you start a Chromium test with Playwright, the browser will by default run in headless mode, which means no UI will be visible during testing.
Playwright supports communicating with Chromium based browsers, including Chrome, through the CDP protocol (Chrome DevTools Protocol).
TestingBot provides access to real Chrome browsers, available for your Playwright tests. Simply connect your Playwright tests to the TestingBot browser grid.
Puppeteer and Chromium
Puppeteer is a browser automation framework created and maintained by Google. It provides automation for all Chromium based browsers, including Chrome.
This NodeJS automation framework uses the CDP protocol, Chrome DevTools Protocol, to communicate with local or remote Chromium-based browsers.
TestingBot provides a browser grid of real Chrome browsers, available for your Puppeteer testing. Your Puppeteer tests simply connect, through CDP, to the TestingBot browser grid.