@vercel/og

What is @vercel/og?

@vercel/og is a package designed to generate Open Graph images dynamically. It allows developers to create custom social media preview images on the fly using HTML and CSS, which can be particularly useful for generating unique images for each page or post on a website.

What are @vercel/og's main functionalities?

Generate Open Graph Images

This feature allows you to generate Open Graph images dynamically using HTML and CSS. The code sample demonstrates how to create an image with a custom title passed as a query parameter.

const { ImageResponse } = require('@vercel/og');

export default function handler(req, res) {
  const { searchParams } = new URL(req.url, 'http://localhost');
  const title = searchParams.get('title') || 'Default Title';

  const image = new ImageResponse(
    <div style={{
      fontSize: 128,
      color: 'white',
      background: 'black',
      width: '100%',
      height: '100%',
      display: 'flex',
      alignItems: 'center',
      justifyContent: 'center',
    }}>
      {title}
    </div>,
    {
      width: 1200,
      height: 630,
    }
  );

  res.setHeader('Content-Type', 'image/png');
  res.send(image);
}

Other packages similar to @vercel/og

puppeteer

Puppeteer is a Node library which provides a high-level API to control Chrome or Chromium over the DevTools Protocol. It can be used to generate screenshots and PDFs of web pages, which can include Open Graph images. Compared to @vercel/og, Puppeteer offers more flexibility and control over the browser environment but requires more setup and resources.

html-to-image

html-to-image is a library that allows you to convert HTML nodes to images in various formats. It is simpler and more lightweight compared to @vercel/og, but it may not offer the same level of customization and dynamic content generation capabilities.

sharp

Sharp is a high-performance image processing library for Node.js. It can be used to create, manipulate, and convert images. While it does not directly generate images from HTML/CSS like @vercel/og, it can be used in conjunction with other tools to achieve similar results.

README

@vercel/og

Satori based Open Graph Image generation adapter for Vercel’s Edge Function.

Basic Usage

Install @vercel/og, then use it inside Edge API routes in your Next.js project:

// /pages/api/og.jsx
import { ImageResponse } from '@vercel/og'

export const config = {
  runtime: 'experimental-edge',
}

export default function () {
  return new ImageResponse(
    (
      <div
        style={{
          fontSize: 128,
          background: 'white',
          width: '100%',
          height: '100%',
        }}
      >
        Hello!
      </div>
    )
  )
}

The React element will be rendered and responded as a PNG from that Edge Function endpoint. For more details and restrictions in image generation, see Satori.

API Reference

@vercel/og only supports the Edge Runtime. The Node.js runtime will not work.

The package exposes an ImageResponse constructor, with the following options available:

import { ImageResponse } from '@vercel/og'

// ...
new ImageResponse(
  element: ReactElement,
  options: {
    width?: number = 1200
    height?: number = 800
    emoji?: 'twemoji' | 'blobmoji' | 'noto' | 'openmoji' = 'twemoji',
    fonts?: {
      name: string,
      data: ArrayBuffer,
      weight: number,
      style: 'normal' | 'italic'
    }[]
    debug?: boolean = false

    // Options that will be passed to the HTTP response
    status?: number = 200
    statusText?: string
    headers?: Record<string, string>
  },
)

By default, these headers will be included by @vercel/og:

'content-type': 'image/png',
'cache-control': 'public, immutable, no-transform, max-age=31536000',

You can see the Code Examples section below to see more details.

Code Examples

Hello World

// /pages/api/og.jsx

import { ImageResponse } from '@vercel/og'

export const config = {
  runtime: 'experimental-edge',
}

export default function () {
  return new ImageResponse(
    (
      <div
        style={{
          fontSize: 128,
          background: 'white',
          width: '100%',
          height: '100%',
        }}
      >
        Hello!
      </div>
    )
  )
}

Vercel Docs + TypeScript

https://vercel-og-service.vercel.sh/?title=Creating Deployments

// /pages/api/og.tsx

import { ImageResponse } from '@vercel/og';
import { NextRequest } from 'next/server';

export const config = {
  runtime: 'experimental-edge',
};

export default function handler(req: NextRequest) {
  try {
    const { searchParams } = new URL(req.url);

    // ?title=<title>
    const hasTitle = searchParams.has('title');
    const title = hasTitle
      ? searchParams.get('title').slice(0, 100)
      : 'Vercel Docs';

    return new ImageResponse(
      (
        <div
          style={{
            backgroundColor: 'black',
            backgroundSize: '150px 150px',
            height: '100%',
            width: '100%',
            display: 'flex',
            textAlign: 'center',
            alignItems: 'center',
            justifyContent: 'center',
            flexDirection: 'column',
            flexWrap: 'nowrap',
          }}
        >
          <div
            style={{
              display: 'flex',
              alignItems: 'center',
              alignContent: 'center',
              justifyContent: 'center',
              justifyItems: 'center',
            }}
          >
            <img
              alt="Vercel"
              height={200}
              src="data:image/svg+xml,%3Csvg width='116' height='100' fill='white' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M57.5 0L115 100H0L57.5 0z' /%3E%3C/svg%3E"
              style={{ margin: '0 30px' }}
              width={226.6 * 0.5}
            />
          </div>
          <div
            style={{
              // When the title is very short we increase the font size.
              // We choose 14 here because that'll be the maximum width to keep it
              // one line (14 “W” characters).
              fontSize: title.length < 14 ? 72 : 60,
              fontStyle: 'normal',
              letterSpacing: '-0.025em',
              color: 'white',
              marginTop: 30,
              padding: '0 120px',
              lineHeight: 1.4,
              whiteSpace: 'pre-wrap',
            }}
          >
            {title}
          </div>
        </div>
      ),
      {
        width: 1800,
        height: 900,
      },
    );
  } catch (e) {
    return new Response(`Failed to generate the image: ${e.message}`, {
      status: 500,
    });
  }
}

Dynamic Image

import { ImageResponse } from '@vercel/og'

export const config = {
  runtime: 'experimental-edge',
}

function arrayBufferToBase64(buffer) {
  let binary = ''
  const bytes = new Uint8Array(buffer)
  for (let i = 0; i < bytes.byteLength; i++) {
    binary += String.fromCharCode(bytes[i])
  }
  return btoa(binary)
}

export default async function (req) {
  const { searchParams } = req.nextUrl
  const username = searchParams.get('username')
  if (!username) {
    return new ImageResponse(<>Visit with "?username=vercel"</>, {
      width: 1200,
      height: 600,
    })
  }

  const avatarResponse = await fetch(`https://github.com/${username}.png`)
  const avatarImageType = avatarResponse.headers.get('content-type')
  const avatar = arrayBufferToBase64(await avatarResponse.arrayBuffer())

  return new ImageResponse(
    (
      <div
        style={{
          fontSize: 60,
          color: 'black',
          background: '#f6f6f6',
          width: '100%',
          height: '100%',
          paddingTop: 50,
          flexDirection: 'column',
          justifyContent: 'center',
          alignContent: 'center',
          alignItems: 'center',
        }}
      >
        <img
          width='256'
          height='256'
          src={`data:${avatarImageType};base64,${avatar}`}
          style={{
            borderRadius: 128,
          }}
        />
        <p>github.com/{username}</p>
      </div>
    ),
    {
      width: 1200,
      height: 600,
    }
  )
}

Emoji

import { ImageResponse } from '@vercel/og'

export const config = {
  runtime: 'experimental-edge',
}

export default async function () {
  return new ImageResponse(
    (
      <div
        style={{
          fontSize: 100,
          color: 'black',
          background: 'white',
          width: '100%',
          height: '100%',
          padding: '0 200px',
          textAlign: 'center',
          justifyContent: 'center',
          alignContent: 'center',
        }}
      >
        👋, 🌎
      </div>
    ),
    {
      width: 1200,
      height: 600,
      // Supported options: 'twemoji', 'blobmoji', 'noto', 'openmoji'
      // Default to 'twemoji'
      emoji: 'twemoji',
    }
  )
}

Image SVG

import { ImageResponse } from '@vercel/og'

export const config = {
  runtime: 'experimental-edge',
}

export default async function () {
  return new ImageResponse(
    (
      <div
        style={{
          fontSize: 40,
          color: 'black',
          background: 'white',
          width: '100%',
          height: '100%',
          padding: '0 200px',
          textAlign: 'center',
          justifyContent: 'center',
          alignContent: 'center',
        }}
      >
        <img
          width='284'
          height='65'
          src="data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='black' height='65' viewBox='0 0 284 65'%3E%3Cpath d='M141.68 16.25c-11.04 0-19 7.2-19 18s8.96 18 20 18c6.67 0 12.55-2.64 16.19-7.09l-7.65-4.42c-2.02 2.21-5.09 3.5-8.54 3.5-4.79 0-8.86-2.5-10.37-6.5h28.02c.22-1.12.35-2.28.35-3.5 0-10.79-7.96-17.99-19-17.99zm-9.46 14.5c1.25-3.99 4.67-6.5 9.45-6.5 4.79 0 8.21 2.51 9.45 6.5h-18.9zm117.14-14.5c-11.04 0-19 7.2-19 18s8.96 18 20 18c6.67 0 12.55-2.64 16.19-7.09l-7.65-4.42c-2.02 2.21-5.09 3.5-8.54 3.5-4.79 0-8.86-2.5-10.37-6.5h28.02c.22-1.12.35-2.28.35-3.5 0-10.79-7.96-17.99-19-17.99zm-9.45 14.5c1.25-3.99 4.67-6.5 9.45-6.5 4.79 0 8.21 2.51 9.45 6.5h-18.9zm-39.03 3.5c0 6 3.92 10 10 10 4.12 0 7.21-1.87 8.8-4.92l7.68 4.43c-3.18 5.3-9.14 8.49-16.48 8.49-11.05 0-19-7.2-19-18s7.96-18 19-18c7.34 0 13.29 3.19 16.48 8.49l-7.68 4.43c-1.59-3.05-4.68-4.92-8.8-4.92-6.07 0-10 4-10 10zm82.48-29v46h-9v-46h9zM37.59.25l36.95 64H.64l36.95-64zm92.38 5l-27.71 48-27.71-48h10.39l17.32 30 17.32-30h10.39zm58.91 12v9.69c-1-.29-2.06-.49-3.2-.49-5.81 0-10 4-10 10v14.8h-9v-34h9v9.2c0-5.08 5.91-9.2 13.2-9.2z'%3E%3C/path%3E%3C/svg%3E"
        />
      </div>
    ),
    {
      width: 1200,
      height: 600,
    }
  )
}

Different Languages

import { ImageResponse } from '@vercel/og'

export const config = {
  runtime: 'experimental-edge',
}

export default async function () {
  return new ImageResponse(
    (
      <div
        style={{
          fontSize: 40,
          color: 'black',
          background: 'white',
          width: '100%',
          height: '100%',
          padding: '0 200px',
          textAlign: 'center',
          justifyContent: 'center',
          alignContent: 'center',
        }}
      >
        👋 Hello 你好 नमस्ते こんにちは สวัสดีค่ะ 안녕 добрий день Hallá
      </div>
    ),
    {
      width: 1200,
      height: 600,
    }
  )
}