How to control SVG icon size and colour in context

A while back I read a great SVG icon tip from Andy Bell which I’d been meaning to try and finally did so today. Andy recommended that for icons with text labels we set the width and height of the icons to 1em since that will size them proportionately to the adjacent text and additionally lets us use font-size to make any further sizing tweaks.

As previously mentioned, I’ve recently been working on my SVG skills.

Andy Bell’s SVG icon-sizing technique is really clever and feels like it adds lots of flexibility and future-friendliness so I was keen to try it out.

Here’s how it works.

The HTML:

<a class="call-to-action" href="/">
  <span>I’m a link</span>
    <svg 
    class="cta-icon" 
    aria-hidden="true" 
    width="1em" 
    height="1em" 
    viewBox="0 0 14 13" 
      xmlns="http://www.w3.org/2000/svg">
      <path 
      fill="currentColor" 
      fill-rule="evenodd" 
        d="M3.49.868l7.683 3.634a2 2 0 0 1 .052 3.59l-7.682 3.913a2 2 0 0 1-2.908-1.782V2.676A2 2 0 0 1 3.49.868z">
    </path>
  </svg>
</a>

<a class="call-to-action call-to-action-alt" href="/">
  <span>I’m a large link</span>
    <svg 
    class="cta-icon" aria-hidden="true" 
    width="1em" height="1em" 
    viewBox="0 0 14 13" 
      xmlns="http://www.w3.org/2000/svg">
      <path 
      fill="currentColor" 
      fill-rule="evenodd" 
        d="M3.49.868l7.683 3.634a2 2 0 0 1 .052 3.59l-7.682 3.913a2 2 0 0 1-2.908-1.782V2.676A2 2 0 0 1 3.49.868z">
    </path>
  </svg>
</a>

The CSS:

a { color: rgb(183, 65, 14); }

a:hover { color: #6A2000; }

.call-to-action {
  display: inline-flex;
  align-items: center;
  font-weight: bold;
}

.call-to-action-alt {
  font-size: 2rem; 
}

.cta-icon {
  margin-left: .5em;
  font-size: .8em;
}

Here are my key takeaways:

• By applying width and height of 1em to our icon it is predictably sized by default.
• It can now have its size further tweaked in CSS using font-size, for example with ems (where 1em = the font-size of the parent anchor element).
• This technique requires the viewbox attribute being present on the svg.
• Apply the width and height =1em as inline attributes on the svg. We could apply them using CSS, however the inline approach avoids potentially massive icons showing in cases where CSS doesn’t load.
• To get the colour matching, apply fill="currentColor" as an inline attribute on the svg’s path.
• Now, when you apply a hover colour to the anchor in CSS, the icon will just pick that up. Nice!
• Applying inline-flex to the anchor makes the vertical-alignment of text and icon easier.
• Apply aria-hidden to the icon because it’s mainly decorative so we don’t want it read out by screen readers.

And here’s a demo I created to test-drive the technique.