Moving to a system font stack in WordPress (how and why)

I’m a big fan of web performance. But I also don’t think it should or have to compromise design. There is always a good balance in the middle. Back in 2017, I was on GitHub’s blog and was digging their font. It was super easy to read. So I dug into the properties with Chrome Devtools and saw that they were using a system font stack. 

I’ve been using system fonts for years now and love them. So today, I want to show you how to use a system font stack on your WordPress site.

What is a system font stack?

There are different types of fonts to choose from for a website. You pretty much have four different options:

• Web-safe fonts: Free and no download time required by the browser, but typically look dated and therefore aren’t used a lot. Nobody really likes Arial or Tahoma, do they? See a full list of web-safe fonts.
• Web fonts: Look beautiful, but require download by the browser. Have both free and premium options available. Adds to the overall page weight of your website. However, they can be served from cached CDN. Providers include Google, Adobe Fonts (TypeKit), etc.
• Host web fonts locally: Both free and premium options are available. It still requires download time and can take advantage of a single HTTP/2 connection on cached CDN. All major browsers now have separate cache partitioning, so hosting them locally is actually better for performance. You can host your Google fonts locally with Perfmatters.
• System fonts: Free, look pretty darn good as they match the OS, and no download time required! They are used by Weather.com, GitHub, Bootstrap, Medium, Ghost, Booking.com (read their system font story), PubMed, and even your WordPress dashboard. In my personal opinion system fonts look slightly better on macOS versus Windows.

System fonts are nothing new. In fact, Medium was using them in 2015. They feel just like your OS because they are using native fonts. Many modern operating systems choose fonts very wisely, and all have a very sleek look and feel to them. It’s not like defaulting back to a web-safe font of Arial or Times New Roman. Trust me; nobody wants to see Times New Roman on a website.

And best of all, system fonts work just like web-safe fonts, in that they don’t require any download time by the browser. This can help reduce the overall page weight on your website. As of April 2022, web fonts, on average, account for around 6.07% of a total website’s weight. While this is not huge, remember that every little optimization you make adds to a speedy website, especially on mobile.

Are there any disadvantages to using system fonts? No! That’s the beauty of it. Warnings in PageSpeed Insights like “Ensure text remains visible during font load” never even come into play, because technically there is nothing being downloaded.

System font stack CSS

With the font-family property with web fonts, you typically have your primary font and one or two fallback fonts. With system fonts, you have to include all of the different operating systems, and therefore you have to stack quite a few more fonts. This is why it is called a “system font stack.”

For example, here is how CSS might appear with a web font.

font-family: "Open Sans","Helvetica Neue",sans-serif;

And here is how a system font stack might look. The good news is, they aren’t all loading; it’s just an order of which fonts should load from the OS if they are available.

font-family: -apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol"

Did you know your WordPress dashboard uses a system font stack? Here is what they are using.

font-family: -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Oxygen-Sans,Ubuntu,Cantarell,"Helvetica Neue",sans-serif

CSS-Tricks also has an alternative method on how to apply system fonts using @font-face.

System font stack cheatsheet

This is where you have to choose which setup you want. Here is a list of which fonts go with each operating system. Note: This changes over time, so you might need to revisit your fonts as new operating systems emerge. I will make sure to keep this list updated.

System Font	OS
-apple-system (San Francisco)	iOS Safari, macOS Safari, macOS Firefox
system-ui	macOS Chrome, Windows Chrome (new versions)
BlinkMacSystemFont (San Francisco)	macOS Chrome
Segoe UI	Windows Vista and newer
Tahoma	Windows XP
Roboto	Android, Chrome OS
Oxygen / Oxygen-Sans	KDE
Fira Sans	Firefox OS
Droid Sans	Android (old versions)
Ubuntu	Ubuntu
Cantarell	GNOME
Helvetica Neue	macOS versions < 10.11
Arial	All
sans-serif	All

How to implement a system font stack

I use a system font stack here on woorkup.com, and on all of my other websites. I feel like I have finally found the best of both worlds. And here’s how I did it.

Option 1: Use the GeneratePress WordPress theme

Want to make this super easy? Just move to the GeneratePress theme, which is what I use on all of my websites. In the customizer, under Typography, you can simply select “System Stack.” And that’s it!

Other performance-focused themes like Astra also have the option to use system fonts.

Option 2: Add system font stack with CSS

If you’re using another WordPress theme, you can easily move to a system font stack with a bit of CSS.

Step 1

In WordPress, you’ll need to change the CSS on your font-family. You can use the WordPress customizer to add the code, under “Additional CSS.”

Step 2

Enter the following code. This might vary per theme, but for most, the following should override everything. I’m using the same system font stack as GithHub, except I’m adding system-ui as newer versions of Chrome support that. Remember, they will be used in the order they appear in the stack.

body {font-family: -apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";}
h1,h2,h3,h4,h5,h6 {font-family:-apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";}

Depending on your theme, you might need to add paragraph tags for the body content. So it would be this:

body, p {font-family: -apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";}

Step 3

You will also want to disable any 3rd party fonts, such as Google Fonts, that you have loaded from your WordPress theme. This again can vary, as each developer includes fonts differently. But many themes now have an easy way to toggle Google Fonts on or off.

If you use one of the default WordPress themes, you can easily use the free Disable Google Fonts plugin. Or you can also disable Google fonts in our Perfmatters plugin.

Before and after speed tests

And, of course, I couldn’t resist. Here are before and after speed tests. Each test was run five times, and an average was taken.

Speed test before

Here is the speed test before, when I had Google fonts loading.

Speed test after

Here is the speed test after using my system font stack. As you can see, I dropped my entire page weight by about 60 KB and got rid of three requests. One to fonts.googleapis.com and then two downloads for different font-weight versions of Roboto. The system font stack was about 6% faster than using Google fonts.

I know a lot of sites that use 4-5 different font weights or styles, and sometimes even 2-3 different Google fonts. So you could potentially see even more significant improvements than even I did.

I also moved our novashare.io WordPress site to system fonts and had great results; check out this speed test below.

Font smoothing

Font smoothing comes down to personal preference. When you apply antialiasing, your font will be a little thinner and lighter. I’m not using it on this site as I prefer the slightly thicker font; I think it feels a little warmer. But you can experiment with both to see which one you like.

You can add this to the body.

body {
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
}

Summary

System fonts can be a great alternative to web fonts and web-safe fonts. I still really like the look of my font, and now I know it’s not causing any load for users. Even though Google fonts can be hosted locally, it’s still part of the overall page weight.

Curious what your thoughts are? Have you used a system font stack yet with WordPress? If so, let me know below.