Once you release Beta version, does it get any new fixes before going into Release?
Suppose that I am testing Beta Version 50 today and certified that my website works fine. Is there any change in this version before it get pushed to Release?
If no, then I can safely assume that I have tested the new version for Firefox and doesn't need any change.
If yes, then I will have to keep eye on all the changes and again test my website on intermediate Beta version and Release version?
Wšykne wótegrona (5)
You might find this website helpful: https://www.fxsitecompat.com/en-CA/
Beta isn't static; as long as Updates aren't disabled. It receives multiple updates until it is actually Released. Six to 8 Beta versions are typical, but there's no set limit; it depends on "check-ins" on the Beta channel. And typically there are 2 or 3 RC (Release Candidate) versions in the 7 to 10 days before Release. RC is technically a Beta version, but it changes to the the Release channel after Release is made. IOW, Beta always updates to the next full Beta version, whereas RC will update to the Release channel and be on the Release channel after that version hits Release status.
As an editorial comment on the above:
The changes made during the three weeks before the anticipated release date usually are minor bug fixes, but occasionally there is a surprise like a bug fix causing a new issue, or a whole feature delayed because it isn't ready yet. If you can't afford any glitches, it's a good idea to test again toward the end of the cycle.
For the Beta channel there can be say six to twelve Beta builds for a version on channel with nine or ten builds being common lately. Sometimes the first couple Beta builds of a version on channel can have issues until cleared up in next builds.
The Release Candidate builds will have one build at minimum or multiple builds even for QA testing if need be. The last RC build of a version becomes the Release.
Release < Beta (b#) < Aurora (a2) (aka developers edition) < Nightly (a1)
The Aurora and Nightly channels are potentially more unstable as they can get checkins almost everyday so they get a update each of those days. Sometimes this can create issue(s) until fixed, finished or reverted.
Above replies trigger another questions. If I am being proactive to fix any issue on Prod version of firefox, when should I take Beta to make sure that I never see new surprises in Prod version.
What is the time period in final Beta version to Release in prod?
Cycles are generally six weeks, sometimes a bit longer. This page has the current calendar: https://wiki.mozilla.org/RapidRelease/Calendar -- I suggest starting in the middle with "Release Date" to see the next mainstream release (column to the right) and beta (column to the left).