Reading · Joel M Turner · RSS Amplifier

Astro has first-party support for loading fonts in a performant way. Until recently, we often reached for the community Astro Font package which is still fine for existing sites, but new projects should prefer the built-in fonts configuration in astro.config so providers and variants stay aligned with Astro releases.

The old flow was an integration-style workflow, whereas the first-party API declares local files or providers in one place, creates CSS variables, and avoids an extra dependency for the same performance.

Using a custom font

You can load a local font or from a provider with a quick update to the astro.config.mjs.

From a local file

import { defineConfig, fontProviders } from "astro/config";
export default defineConfig({
  fonts: [
    {
      provider: fontProviders.local(),
      name: "SweetCandy",
      cssVariable: "--font-sweet-candy",
      options: {
        variants: [
          {
            src: ["./src/assets/fonts/SweetCandy.woff2"],
            weight: "normal",
            style: "normal",
          },
        ],
      },
    },
  ],
});

From a Provider

import { defineConfig, fontProviders } from "astro/config";
export default defineConfig({
  fonts: [
    {
      provider: fontProviders.fontsource(),
      name: "Roboto",
      cssVariable: "--font-roboto",
    },
  ],
});

Using the font

Now that we have the font configured we can add this to our site for use. A great way to do this is in our layout component’s head section.

---
import { Font } from "astro:assets";
---
<html>
  <head>
    <Font cssVariable="--font-sweet-candy" />
  </head>
  <body>
    <slot />
  </body>
</html>

Once that’s in place, any page that uses that head will be able to grab the css variable and apply it wherever needed.

---
import Layout from "../layouts/Layout.astro";
---
<Layout>
  <h1>In a world...</h1>
  <p>The great Candy Queen has given the people a new...</p>
  <style>
  h1 {
    font-family: var(--font-sweet-candy);
  }
  </style>
</Layout>

Optimization

It’s sometimes necessary to have a font preloaded, especially if that font is largely above the fold. The one caveat here is that it can slow the rendering of the page since it’s a blocking request so it’s best to use it only if needed. In this case, we can add the preload attribute to the Font loading in the head.

<Font cssVariable="--font-sweet-candy" preload />

Tailwind

I’m currently using Tailwind v4 on this site and it can use the variable as well.

@theme inline {
  --font-family-fira-code: var(--font-fira-code);
  --font-family-fira-sans: var(--font-fira-sans);
}

Fonts in Astro: Optimize Performance of Fonts via Astro