Chrome, Firefox, and Edge are all approaching version 100, which could disrupt some websites. Some websites that aren’t ready to accept triple-digit user-agent strings may have errors or compatibility issues as a result of the switch to version 100 in the coming weeks. Google, Mozilla, and Microsoft are all working hard to avoid any major problems.
Some may be reminded of the historic Y2K bug and Microsoft skipping the release of Windows 9, but this time the problem is with how websites read user-agent (UA) strings to identify web browsers and their capabilities.
For months, Mozilla, Google, and Microsoft have been warning about the imminent version 100 release, which will be available in March for Chrome and Edge, and in May for Firefox. Both Mozilla and Google have been conducting tests to evaluate websites and report errors. There’s a running list of issues, which is currently quite short, and Engadget reports that HBO Go, Bethesda, and Yahoo are among the notable sites affected.
“When browsers first reached version 10 a little over 12 years ago, many issues were discovered with User-Agent parsing libraries as the major version number went from one digit to two. Without a single specification to follow, different browsers have different formats for the User-Agent string and site-specific User-Agent parsing. It’s possible that some parsing libraries may have hard-coded assumptions or bugs that don’t take into account three-digit major version numbers,” explains a team of web developers in a Mozilla blog.
While there are fears about some websites crashing, a lot of hard work has been done behind the scenes to make the transition to version 100 go smoothly — much like what happened to avoid big issues with the Y2K bug 22 years ago. Developers can use a specific setting in current versions of Chrome, Edge, and Firefox to make the browsers report as version 100, which will help with site testing.
In the event of widespread problems, there are also contingency plans in place. If the problems grow too extensive to manage, Mozilla says it would either repair the broken websites right away or briefly freeze Firefox’s version at 99. Google’s backup plan is to utilize a flag to freeze the major version at 99, while Microsoft hasn’t reported a backup plan yet.