There is a vertically aligned rectangle. The left and right sides are longer than the top/bottom sides. In the top right corner there is a small right triangle built into the rectangle, creating a diagonal line in place of part of the top and right sides. In the middle of the rectangle are the letters 'HTML'
Related to HTML Filetype Icon
Related icons are the icons with matching tags, as well as all files icons. All icons are in the same flat style. You can either download free PNG icons or buy SVG vectors