Thomas Ledoux

Posted on Feb 15, 2021 • Edited on Nov 28, 2022 • Originally published at thomasledoux.be

The best way to load and use Google Fonts in Next.js + Tailwind

#nextjs #css #javascript #performance

I was setting up a new project today with Next.js and tailwindcss, and I had to use Roboto as a font.

Since it's a Google Font, I was looking into the best way to load a font from an external URL (since the fonts are available through a CDN, I don't bother hosting them myself).

The following article explains this very thoroughly: https://csswizardry.com/2020/05/the-fastest-google-fonts.

From this article you can derive the following snippet:

<link rel="preconnect"
      href="https://fonts.gstatic.com"
      crossorigin />

<!-- [2] -->
<link rel="preload"
      as="style"
      href="https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap" />

<!-- [3] -->
<link rel="stylesheet"
      href="https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap"
      media="print" onload="this.media='all'" />

<!-- [4] -->
<noscript>
  <link rel="stylesheet"
        href="https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap" />
</noscript>

Also note how I only include the weights I'm going to be using (400 & 700) to reduce the size of the font we're loading.

So, how do we implement the above snippet into our Next.js application?
That's quite simple!
In your /pages folder, you should have a _document.js/.tsx file.
In this file, we can easily adapt the <head> section using the next/head module. This will be applied on every page by Next.js.

import Document, {
  DocumentContext,
  Html,
  Head,
  Main,
  NextScript,
} from 'next/document'

class MyDocument extends Document {
  static async getInitialProps(ctx: DocumentContext) {
    const initialProps = await Document.getInitialProps(ctx)

    return initialProps
  }

  render() {
    return (
      <Html>
        <Head>
          <link
            rel="preconnect"
            href="https://fonts.gstatic.com"
            crossOrigin="true"
          />
          <link
            rel="preload"
            as="style"
            href="https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap"
          />
          <link
            rel="stylesheet"
            href="https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap"
            media="print"
            onLoad="this.media='all'"
          />
          <noscript>
            <link
              rel="stylesheet"
              href="https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&display=swap"
            />
          </noscript>
        </Head>
        <body>
          <Main />
          <NextScript />
        </body>
      </Html>
    )
  }
}

export default MyDocument

Now the Next.js part is done. The font is being loaded, yay!
The next and final part is actually using the font in Tailwind, and applying it to all our sans-serif text (since Roboto is a sans-serif font).

This is super easy in Tailwind, this just requires an extension of the default theme:

const defaultTheme = require('tailwindcss/defaultTheme')

module.exports = {
  theme: {
    extend: {
      fontFamily: {
        sans: ['Roboto', ...defaultTheme.fontFamily.sans],
      },
    },
  },
  variants: {
    extend: {},
  },
  plugins: [],
}

I only needed to add the sans property of the fontFamily object to include the Roboto font, and add the other sans-serif fonts from the default theme as fallbacks.

There you have it! Optimized font loading in your Next.js application with Tailwind :-)
Enjoy.

Top comments (13)

Andrej Gajdos • Jun 2 '21

I am getting Lighthouse warning message:

Warnings: A <link rel=preconnect> was found for "fonts.gstatic.com" but was not used by the browser. Only use preconnect for important origins that the page will certainly request.

Thomas Ledoux • Jun 2 '21

Can you see any requests going to fonts.gstatic.com in your network tab?
Maybe Google changes the CDN for their fonts...

Andrej Gajdos • Jun 2 '21 • Edited

Yes, I see imgur.com/a/zAnDtoE

Thomas Ledoux • Jun 2 '21

That’s strange… not sure why it’s giving that warning then

Andrej Gajdos • Jun 3 '21

I guess Lighthouse changed something, but thanks for the blog post anyway.

Marc • Feb 21 '21

Thanks for sharing. AFAIK, these is no pages/_document file by default, you have to create it yourself to override the default behavior.
But I'm wondering: is it really necessary here to start using a customized _document? You could also use next/head in pages/_app to add the code snippet to the head.

Pablo • Mar 23 '21

I think it is totally allowed.

Check this out: npmjs.com/package/next-google-font...

Thomas Ledoux • Feb 22 '21

Hey Marc,

I haven't tested this with pages/_app yet, but I assume it would work too since you would inject the code into the

section with next/head on every page.

Gabriel Linassi • Nov 18 '21

There's an eslint rule that recommends to add it to the _document file. See nextjs.org/docs/messages/no-page-c...

Steve Reid • Apr 15 '21

Typescript doesn't like the onLoad="this.media='all'"
I get:
Type 'string' is not assignable to type 'ReactEventHandler'.
Any ideas?

Thomas Ledoux • Apr 15 '21

I noticed this too, but chose to ignore it:

<link
  rel="stylesheet"
href="https://fonts.googleapis.com/css2family=Podkova:wght@400;500;700&Roboto:wght@400;500;700&display=swap"
 media="print"
 // @ts-ignore
 onLoad="this.media='all'"
/>

ninest • May 24 '21

Thanks for the write up! Is it faster if I download the fonts and reference them locally rather than importing from fonts.google.com?

Thomas Ledoux • May 24 '21

My pleasure!
I'm guessing this would be faster, as you don't have to connect to an external source to fetch the fonts.
But the CDN of Google is very fast, so I'm not sure if the difference will be noticeable.
If you want to host your fonts locally, have a look at this site: google-webfonts-helper.herokuapp.c...

View full discussion (13 comments)