Chrome and Firefox reach version 100 and this might cause problems

Mozilla warns developers that upcoming versions of Firefox 100 and Chrome 100 may cause problems for some websites because of the three-digit number that will appear in a specific part of the User Agent string.

The latter is a small numeric sequence that includes information about the web browser, such as version number, name, software, and the various technologies it uses. This is read by the web pages in order to be displayed in the appropriate way to the user.

For example, the User Agent string of Mozilla Firefox 97 is Mozilla / 5.0 (Windows NT 10.0; Win64; x64; rv: 97.0) Gecko / 20100101 Firefox / 97.0, while Chrome 98 is Mozilla / 5.0 (Windows NT 10.0; Win64 ; x64) AppleWebKit / 537.36 (KHTML, like Gecko) Chrome / 98.0.4758.82 Safari / 537.36

Google and Mozilla have already started testing to avoid problems, as among the websites that will be difficult are large brands such as HBO Go, Bethesda, Yahoo, Slack etc. One of the suggestions under consideration is to freeze the number 99 in the User Agent string, regardless of whether the latest version with a three-digit number will run normally.

Note that Google Chrome 100 is expected on March 29, 2022 and Mozilla Firefox 100 on May 3, 2022.