What is a good button font?
Sans-serif font is the standard for all kinds of buttons. That's because sans-serif fonts are very readable for every online usage. (On the flip side, serif fonts are better for print publications.) You want the copy on your button to be as readable as possible, as it is the most important piece of text on the page.
What should you consider when choosing fonts for web sites?
When choosing web fonts, you often have to weigh several considerations together. While the length of your text helps determine which font you select, the size at which you're setting type is another important factor. At relatively small sizes, up to 16pt, try sans serif options like Roboto, Montserrat and Raleway.