This can be done in two ways: either simply increase or decrease the page zoom, or change in the options that on the Internet show a specific, pre-selected font, not the font of the website.
If you are a user of Mozilla Firefox, for the first option, go to the browser in "View" - "Zoom" and select what you need - "Increase" or "Decrease". You can simply use "hotkeys" by pressing "ctrl and +" to zoom in or "ctrl and –" to zoom out. To select a specific font , go to "Tools" - "Settings". Go to the Content tab and under Fonts and colors choose your desired type font and size, then right click on the "Advanced" button and uncheck the box next to "Allow websites to choose their own fonts, instead of my selections above". After clicking on "OK" the font will change immediately.
Users of the Opera browser: To zoom in, go to "Page" - Zoom and choose the zoom in its percentage. Or just use "hot keys" listed above. For the second method, go to "Settings" - "General settings" tab, "Web pages". Here choose settings for the "Normal font". To do this, click on the name of the type font and change the size and other parameters if necessary. It is also possible to set "fixed width font" (a font in which all characters have the same width). Click OK and the new font is ready.
For Internet Explorer the first method is the same as for Mozilla Firefox. But there is another option: go to "View" - " font" and choose one of five fonts.