Google Chrome and Mozilla Firefox are probably the most used web browsers on plant earth. Google and Mozilla frequently release new updates to their web browser, bumping the version number every time. Both the web browsers are about to hit version 100, and some people are worried that the new version number may break some of the websites.

Web browsers have a property called "User Agent". This property contains information like web browser, operating system, and CPU architecture, which allows the websites to identify the browser being used by the visitor. There's no standard way of declaring "User Agent", though over the years it has become quite long. Here is a sample of a User Agent string:

        Mozilla/5.0 (Macintosh; Intel Mac OS X 12_2_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.102 Safari/537.36
    

Many libraries for the web make use of the web browser version number and name to work. However, not all were coded with three-digit major version numbers in mind. This could cause some of the websites to break and not work as they should.

Thankfully, both Google and Mozilla were prepared for this. Both the companies have been working on mitigation strategies (via Bleeping Computer). Google Chrome and Mozilla Firefox have been running some experiments during the past few months and weeks that changed some user agents to v100. This has led to many bug reports and some fixes.

In case some websites still break, both Google and Mozilla have a backup plan. Mozilla will freeze the version number at version 99 for the websites that break. Google, on the other hand, will change its way of version numbering by moving the release number to second place (e.g. 99.101.4988.0 for Chrome 101).

Via: Engadget, XDA Developers