Firefox and Chrome's dev and beta releases are automatically updated when new releases are made by each project. However, as is the nature of betas, sometimes the beta breaks compatibility with Selenium, making it impossible for Sauce Labs to use. Because Firefox, Chrome, and Selenium are all Open Source projects, not under the control of Sauce Labs, we're unable to set project direction and ensure this functionality never breaks.
End users rarely install beta or dev. Those who do tend to understand that functionality may be missing or broken in these versions. In addition, the beta and dev releases are made available mostly to assist with testing the Selenium functionality of said releases.
Sauce Labs makes very minimal changes to the browsers we offer. We also take care to offer exactly what we say we do. Making custom patches to Firefox, Chrome, or Selenium would make them no longer reflect reality. If Sauce Labs can't spin up beta or dev with Selenium, it's likely that this functionality doesn't work locally on all platforms. We also don't want to offer a beta or dev release that isn't the same as the project's current beta or dev release, because that would just lead to confusion.
We recommend customers testing commercial web applications for end user consumption stick to released versions of browsers. These have passed testing by their authors, the Selenium project and Sauce Labs, and are known to have, at the very least, passed the Selenium and Sauce Labs test suites.
Firefox Release Process
Sauce Labs pulls from these three release channels.
The official "Release" version, a stable and commonly used version that most consumers will use. Mozilla has more information here: https://www.mozilla.org/en-US/firefox/channel/desktop/
The Beta version:
From Mozilla's site: "Beta is an unstable testing and development platform. By default, Beta sends data to Mozilla — and sometimes our partners — to help us handle problems and try ideas."
The Dev version:
From Mozilla's site: "Developer Edition is an unstable testing and development platform. By default, Developer Edition sends data to Mozilla — and sometimes our partners — to help us handle problems and try ideas."
Chrome Release Process
The Chrome Project follows a similar release process. t uses a Stable, Dev, and Beta version described on their official project page https://www.chromium.org/getting-involved/dev-channel:
- Stable channel: This channel has gotten the full testing and blessing of the Chrome test team, and is the best bet to avoid crashes and other issues. It's updated roughly every two-three weeks for minor releases, and every 6 weeks for major releases.
- Beta channel: If you are interested in seeing what's next, with minimal risk, Beta channel is the place to be. It's updated every week roughly, with major updates coming every six weeks, more than a month before the Stable channel will get them.
- Dev channel: Want to see what's happening quickly, then you want the Dev channel. The Dev channel gets updated once or twice weekly, and it shows what we're working on right now. There's no lag between major versions, whatever code we've got, you will get. While this build does get tested, it is still subject to bugs, as we want people to see what's new as soon as possible.