Try These
Press "Ctrl" and "+" to zoom in on a Web page.
Press "Ctrl" and "_" to zoom out on a Web page.
Click and hold down "Ctrl" and use your mouse's scroll wheel to zoom in and out on a Web page by scrolling up to zoom in and scrolling down to zoom out.
If it is simply the web browser that does not fit your monitor screen, then click on the small button that contains two small squares with one in front of the other, arranged in a diagonal orientation, which is located in the top-right corner of the web browser. This will maximize the web browser window so that it fits the entire screen.