Many browsers disguise themselves by presenting userAgent
strings which are similar to those of more popular browsers. Sometimes browsers do this
1 so that sites with poor browser sniffers will render pages as popular browsers will;
and sometimes browsers do this 2 so that sites which try to sabotage enemy browsers will fail to do so.
Examples are:
Opera: many poor browser sniffers have failed to detect Opera correctly, resulting in pages being rendered poorly, so Opera Software
has repeatedly changed the Opera userAgent
string in order to adapt to lousy browser sniffers.
Vivaldi: enemies of Vivaldi such as FaceBook, Google, and Microsoft 1 deliberately sabotaged Vivaldi by presenting broken code to Vivaldi,
or 2 refused to allow Vivaldi users to use their sites.
Consequently, starting with Vivaldi v2.10, Vivaldi Technologies began presenting the same userAgent
string as
the Chrome browser, ensuring that its enemies cannot sabotage Vivaldi without also sabotaging Chrome. Unfortunately, this means that 1 good, honest browser sniffers like the one used by my sites will fail to correctly identify
Vivaldi users; and 2 browser statistics will fail to correctly count the number of Vivaldi users, making Vivaldi appear to be much less popular than it really is.
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In addition, some browsers disguise themselves as other browsers for unknown reasons. An example is Brave, which identifies itself as Chrome.