Using a custom font in your OG Image

You can use the following code sample to explore using parameters and different content types with next/og. To learn more about OG Image Generation, see Open Graph Image Generation.

Create an api route with route.tsx in /app/api/og/ and paste the following code:

app/api/og/route.tsx

import { ImageResponse } from 'next/og';
// App router includes @vercel/og.
// No need to install it.
 
async function loadGoogleFont (font: string, text: string) {
  const url = `https://fonts.googleapis.com/css2?family=${font}&text=${encodeURIComponent(text)}`
  const css = await (await fetch(url)).text()
  const resource = css.match(/src: url\((.+)\) format\('(opentype|truetype)'\)/)
 
  if (resource) {
    const response = await fetch(resource[1])
    if (response.status == 200) {
      return await response.arrayBuffer()
    }
  }
 
  throw new Error('failed to load font data')
}
 
export async function GET() {
  const text = 'Hello world!'
 
  return new ImageResponse(
    (
      <div
        style={{
          backgroundColor: 'white',
          height: '100%',
          width: '100%',
          fontSize: 100,
          fontFamily: 'Geist',
          paddingTop: '100px',
          paddingLeft: '50px',
        }}
      >
        {text}
      </div>
    ),
    {
      width: 1200,
      height: 630,
      fonts: [
        {
          name: 'Geist',
          data: await loadGoogleFont('Geist', text),
          style: 'normal',
        },
      ],
    },
  );
}

If you're not using a framework, you must either add "type": "module" to your package.json or change your JavaScript Functions' file extensions from .js to .mjs

Preview the OG route locally by running the following command:

pnpm dev

Then, browse to http://localhost:3000/api/og. You will see the following image:

Image generated using the custom font typewriter

Using a custom font in your OG Image

More resources