Font Awesome 5 unicode

Question

Font Awesome 5 star icon has and different is fas , far

Answer 1

^{If you are using the JS+SVG version read this: Font Awesome 5 shows empty square when using the JS+SVG version}

The difference between the regular and the solid version is the font-weight. You simply need to adjust this one to swap between both version:

input.star:checked ~ label.star:before {
  content: '\f005';
  color: #e74c3c;
  transition: all .25s;
  font-family: 'Font Awesome 5 Free';
  font-weight: 900;
}

label.star:before {
  content: '\f005';
  font-family: 'Font Awesome 5 Free';
  font-weight: 200;
}

Here is another related question Font Awesome 5 on pseudo elements shows square instead of icon for more details.