Google apparently wants to freeze the “user agent string” in the Chrome browser. In this way, servers recognize who is currently visiting the page and can accordingly deliver content accordingly. For example, it looks like this:
Mozilla / 5.0 (Macintosh; Intel Mac OS X 10_15_2) AppleWebKit / 537.36 (KHTML, like Gecko) Chrome / 79.0.3945.117 Safari / 537.36
The makers of the Vivaldi browser recently announced that they removed the name from the string, since some websites were probably displayed incorrectly.
According to Google, the string contains many details about the browser and the device of the user, i.e. passive fingerprint information. In addition to these privacy issues, user agent sniffing is a source of compatibility issues, especially niche browsers, which causes browsers to lie about themselves (generally or when visiting certain websites).
The above fact, according to the developers, makes it desirable to freeze the UA string and replace it with a better mechanism. There have been attempts by the Safari team to freeze the UA string in the past, but without an alternative way to deliver UA-based content, they had to be partially undone.
The “User Agent Client Hints” (UA-CH) seem to prevail for the future. The new technology only provides the required information if the server requests it via secure connections, and only those elements that are really required are requested. As early as the autumn of this year, the new string could work uniformly in Google’s browsers.
A discussion has just started in the Google Group.