Just create the following css style:
html, body {
user-select: text;
}
If you use Chrome, thereThere is an extension called Stylish which allows you to install that (or any other) css code in any website of your choice. Just type in the above css code and tell which website[s] you want it to be applied to and you are good to go. Firefox maybe have a similar extensionThis extension works on Chrome, Baidu, Firefox and Opera. If you happen to be on IE then you are out of luck. But you already know that don't you.