html-pdf-chrome

HTML to PDF or image (jpeg, png, webp) converter via Chrome/Chromium.

Prerequisites

Latest Chrome/Chromium
Windows, macOS, or Linux
A currently supported version of Node.js

Installation

npm install --save html-pdf-chrome

Security

This library is NOT meant to accept untrusted user input. Doing so may have serious security risks such as Server-Side Request Forgery (SSRF).

CORS

If you run into CORS issues, try using the --disable-web-security Chrome flag, either when you start Chrome externally, or in options.chromeFlags. This option should only be used if you fully trust the code you are executing during a print job!

Usage

Note: It is strongly recommended that you keep Chrome running side-by-side with Node.js. There is significant overhead starting up Chrome for each PDF generation which can be easily avoided.

It's suggested to use pm2 to ensure Chrome continues to run. If it crashes, it will restart automatically.

As of this writing, headless Chrome uses about 65mb of RAM while idle.

# install pm2 globally
npm install -g pm2
# start Chrome and be sure to specify a port to use in the html-pdf-chrome options.
pm2 start google-chrome \
  --interpreter none \
  -- \
  --headless \
  --disable-gpu \
  --disable-translate \
  --disable-extensions \
  --disable-background-networking \
  --safebrowsing-disable-auto-update \
  --disable-sync \
  --metrics-recording-only \
  --disable-default-apps \
  --no-first-run \
  --mute-audio \
  --hide-scrollbars \
  --remote-debugging-port=<port goes here>
# run your Node.js app.

TypeScript:

import * as htmlPdf from 'html-pdf-chrome';

const html = '<p>Hello, world!</p>';
const options: htmlPdf.CreateOptions = {
  port: 9222, // port Chrome is listening on
};

// async
const pdf = await htmlPdf.create(html, options);
await pdf.toFile('test.pdf');
const base64 = pdf.toBase64();
const buffer = pdf.toBuffer();
const stream = pdf.toStream();

// Promise
htmlPdf.create(html, options).then((pdf) => pdf.toFile('test.pdf'));
htmlPdf.create(html, options).then((pdf) => pdf.toBase64());
htmlPdf.create(html, options).then((pdf) => pdf.toBuffer());
htmlPdf.create(html, options).then((pdf) => pdf.toStream());

JavaScript:

const htmlPdf = require('html-pdf-chrome');

const html = '<p>Hello, world!</p>';
const options = {
  port: 9222, // port Chrome is listening on
};

htmlPdf.create(html, options).then((pdf) => pdf.toFile('test.pdf'));
htmlPdf.create(html, options).then((pdf) => pdf.toBase64());
htmlPdf.create(html, options).then((pdf) => pdf.toBuffer());
htmlPdf.create(html, options).then((pdf) => pdf.toStream());

View the full documentation in the source code.

Saving as a Screenshot

By default, pages are saved as a PDF. To save as a screenshot instead, supply screenshotOptions. All supported options can be viewed here.

const htmlPdf = require('html-pdf-chrome');

const html = '<p>Hello, world!</p>';
const options = {
  port: 9222, // port Chrome is listening on
  screenshotOptions: {
    format: 'png', // png, jpeg, or webp. Optional, defaults to png.
    // quality: 100, // Optional, quality percent (jpeg only)

    // optional, defaults to entire window
    clip: {
      x: 0,
      y: 0,
      width: 100,
      height: 200,
      scale: 1,
    },
  },
  // Optional. Options here: https://chromedevtools.github.io/devtools-protocol/tot/Emulation/#method-setDeviceMetricsOverride
  deviceMetrics: {
    width: 1000,
    height: 1000,
    deviceScaleFactor: 0,
    mobile: false,
  },
};

htmlPdf.create(html, options).then((pdf) => pdf.toFile('test.png'));

Using an External Site

import * as htmlPdf from 'html-pdf-chrome';

const options: htmlPdf.CreateOptions = {
  port: 9222, // port Chrome is listening on
};

const url = 'https://github.com/westy92/html-pdf-chrome';
const pdf = await htmlPdf.create(url, options);

Using Markdown

import * as htmlPdf from 'html-pdf-chrome';
import * as marked from 'marked';

const options: htmlPdf.CreateOptions = {
  port: 9222, // port Chrome is listening on
};

const html = marked('# Hello [World](https://www.google.com/)!');
const pdf = await htmlPdf.create(html, options);

Using a Template Engine

Pug (formerly known as Jade)

import * as htmlPdf from 'html-pdf-chrome';
import * as pug from 'pug';

const template = pug.compile('p Hello, #{noun}!');
const templateData = {
  noun: 'world',
};
const options: htmlPdf.CreateOptions = {
  port: 9222, // port Chrome is listening on
};

const html = template(templateData);
const pdf = await htmlPdf.create(html, options);

HTTP Headers

Specify additional headers you wish to send with your request via CreateOptions.extraHTTPHeaders.

const options: HtmlPdf.CreateOptions = {
  port: 9222, // port Chrome is listening on
  extraHTTPHeaders: {
    'Authorization': 'Bearer 123',
    'X-Custom-Test-Header': 'This is great!',
  },
};

const pdf = await HtmlPdf.create('https://httpbin.org/headers', options);

Custom Headers and Footers

Note: Requires Chrome 65 or later.

You can optionally provide an HTML template for a custom header and/or footer.

A few classes can be used to inject printing values:

date - formatted print date
title - document title
url - document location
pageNumber - current page number
totalPages - total pages in the document

You can tweak the margins with the printOptions of marginTop, marginBottom, marginLeft, and marginRight.

At this time, you must inline any images using base64 encoding.

You can view how Chrome lays out the templates here.

Example

const pdf = await htmlPdf.create(html, {
  port,
  printOptions: {
    displayHeaderFooter: true,
    headerTemplate: `
      <div class="text center">
        Page <span class="pageNumber"></span> of <span class="totalPages"></span>
      </div>
    `,
    footerTemplate: '<div class="text center">Custom footer!</div>',
  },
});

Trigger Render Completion

There are a few CompletionTrigger types that wait for something to occur before triggering PDF printing.

Callback - waits for a callback to be called
Element - waits for an element to be injected into the DOM
Event - waits for an Event to fire
Timer - waits a specified amount of time
LifecycleEvent - waits for a Chrome page lifecycle event
Variable - waits for a variable to be set to true
Custom - extend htmlPdf.CompletionTrigger.CompletionTrigger

const options: htmlPdf.CreateOptions = {
  port: 9222, // port Chrome is listening on
  completionTrigger: new htmlPdf.CompletionTrigger.Timer(5000), // milliseconds
};

// Alternative completionTrigger options:
new htmlPdf.CompletionTrigger.Callback(
  'cbName', // optional, name of the callback to define for the browser to call when finished rendering.  Defaults to 'htmlPdfCb'.
  5000 // optional, timeout (milliseconds)
),

new htmlPdf.CompletionTrigger.Element(
  'div#myElement', // name of the DOM element to wait for
  5000 // optional, timeout (milliseconds)
),

new htmlPdf.CompletionTrigger.Event(
  'myEvent', // name of the event to listen for
  '#myElement', // optional DOM element CSS selector to listen on, defaults to body
  5000 // optional timeout (milliseconds)
),

new htmlPdf.CompletionTrigger.LifecycleEvent(
  'networkIdle', // name of the Chrome lifecycle event to listen for. Defaults to 'firstMeaningfulPaint'.
  5000 // optional timeout (milliseconds)
),

new htmlPdf.CompletionTrigger.Variable(
  'myVarName', // optional, name of the variable to wait for.  Defaults to 'htmlPdfDone'
  5000 // optional, timeout (milliseconds)
),

License

html-pdf-chrome is released under the MIT License.

westy92/html-pdf-chrome

westy92

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