As one of the three major browsers once compared with chrome and edge (ie), Firefox has not had a good time recently. Recently, Japan’s NHK announced that its video platform nhk+ officially stopped supporting Firefox browser and advised users to use the latest version of chrome, edge or other browsers. Before that, Apple’s business website “business.apple.com” has excluded Firefox from the scope of support. Opening the website with Firefox will pop up the prompt “your browser is not supported”. In addition, many websites have stopped supporting Firefox browser. At present, Firefox users can skip the restriction of the website on the browser by changing the user agent (UA) of the browser, browse the website normally, and there will be no discomfort. With the increase of websites that stop supporting Firefox, this browser, which inherits the mantle of Netscape, is likely to fall into the dilemma of gradual loss of users and gradually disappear from the vision of mainstream users.