HTML to a base64 image with Go and Puppeteer

Heads up before you start

Puppeteer has no Go port. The closest equivalent is chromedp — an actively maintained Go library that drives Chrome over the same DevTools Protocol Puppeteer uses. These examples use chromedp.

Install chromedp

go get github.com/chromedp/chromedp

chromedp drives a Chrome or Chromium you already have installed — it does not download its own browser, and finds the system Chrome automatically. Run the command inside a Go module (go mod init myproject first if you need one). Some examples also import github.com/chromedp/cdproto for DevTools commands — run go mod tidy after adding the code to pull it in.

Get the base64 encoded image of some HTML and print to screen

package main

import (
	"context"
	"encoding/base64"
	"fmt"
	"log"
	"net/url"

	"github.com/chromedp/chromedp"
)

func main() {
	ctx, cancel := chromedp.NewContext(context.Background())
	defer cancel()

	html := "<html><body><h1>Hello World</h1></body></html>"

	var buf []byte
	if err := chromedp.Run(ctx,
		chromedp.Navigate("data:text/html,"+url.PathEscape(html)),
		chromedp.CaptureScreenshot(&buf),
	); err != nil {
		log.Fatal(err)
	}
	fmt.Println(base64.StdEncoding.EncodeToString(buf))
}

Find out how to generate a PNG from HTML with Go and Puppeteer.

That was 27 lines of code — plus a browser to run in production

Keeping headless browsers fed, patched and scaled is a job in itself. We built Urlbox so the same screenshot is one API call:

curl "https://api.urlbox.com/v1/YOUR_API_KEY/png?url=https://example.com"

Try the Urlbox screenshot API — free trial, no browser babysitting.