How to Add HTML and CSS to a PDF in PHP

If you’re looking to convert an HTML page with CSS into a PDF document, there are several tools and libraries available. Depending on your project’s requirements, you may choose a library that fits your needs in terms of speed, compatibility with CSS, or ease of integration into your PHP application.

This blog post will cover some popular tools for converting HTML and CSS into PDF using PHP, including solutions like wkhtmltopdf, mPDF, and more.

1. Using wkhtmltopdf

wkhtmltopdf is one of the most popular tools for converting HTML to PDF. It uses the WebKit rendering engine, which allows it to process modern CSS and JavaScript as it would in a browser.

Steps to Use wkhtmltopdf in PHP:

1. Install wkhtmltopdf:
   You can install it on Linux or Windows by downloading the package from the wkhtmltopdf website.

2. Call the binary from PHP:
   After installing, you can call the wkhtmltopdf binary from PHP using the exec() function.

// Example: Using exec() to call wkhtmltopdf
$html = '<h1>Hello World</h1><p>This is a test PDF</p>';
$file = 'output.pdf';
file_put_contents('input.html', $html);

// Run wkhtmltopdf to convert HTML to PDF
exec("wkhtmltopdf input.html $file");

Advantages:

• Excellent CSS support, including media queries and print styles.
• Handles JavaScript and complex HTML well.

Disadvantages:

• Requires external binaries, which may not always be available in all hosting environments.

2. Using mPDF

mPDF is a PHP library that allows you to generate PDF files from HTML. It supports a wide range of CSS and provides an easy-to-use API for PDF generation directly from PHP scripts.

Installation:

You can install mPDF via Composer:

composer require mpdf/mpdf

Usage:

require_once __DIR__ . '/vendor/autoload.php';

$mpdf = new \Mpdf\Mpdf();
$html = '<h1>Hello World</h1><p>This is a test PDF with mPDF.</p>';
$mpdf->WriteHTML($html);
$mpdf->Output('output.pdf', \Mpdf\Output\Destination::FILE);

Advantages:

• Easy to install and use.
• No need for external binaries.
• Good CSS support for basic styling.

Disadvantages:

• Can struggle with very complex layouts and JavaScript.
• Documentation can be hard to navigate.

3. Using Dompdf

Dompdf is another PHP library for generating PDF from HTML, with basic CSS support.

Installation:

You can install Dompdf via Composer:

composer require dompdf/dompdf

Usage:

require 'vendor/autoload.php';

use Dompdf\Dompdf;

$dompdf = new Dompdf();
$html = '<h1>Hello World</h1><p>This is a test PDF with Dompdf.</p>';
$dompdf->loadHtml($html);
$dompdf->setPaper('A4', 'portrait');
$dompdf->render();
$dompdf->stream('output.pdf');

Advantages:

• Easy to set up and use.
• Generates PDFs directly from HTML.

Disadvantages:

• Limited CSS support compared to wkhtmltopdf.
• Struggles with complex layouts and large HTML files.

4. Using TCPDF

TCPDF is another powerful library for generating PDFs in PHP, offering support for complex document layouts.

Usage:

require_once('tcpdf_include.php');
$pdf = new TCPDF();

// Add a page
$pdf->AddPage();

// Set content
$html = '<h1>Welcome to TCPDF</h1>';
$pdf->writeHTML($html, true, false, true, false, '');

// Output PDF
$pdf->Output('output.pdf', 'I');

Advantages:

• Great for generating complex PDF layouts.
• Supports a wide range of features including barcodes, QR codes, and more.

Disadvantages:

• Less user-friendly for HTML/CSS rendering.
• More complex setup for custom layouts.

5. Chrome/Chromium Headless (Headless Browser)

You can also use headless Chrome or Chromium to generate PDFs from HTML. This method uses Chrome’s built-in rendering engine, providing near-perfect rendering of HTML and CSS.

Command Example:

chrome --headless --print-to-pdf="output.pdf" https://example.com

This solution is extremely accurate for rendering HTML and CSS, but requires access to a Chrome/Chromium binary.

The best solution depends on your needs:

• If you need full CSS and JavaScript support, wkhtmltopdf or Chrome Headless are excellent choices.
• For simpler tasks with decent CSS support, mPDF or Dompdf will work well within your PHP environment.
• If you’re dealing with complex PDF layouts, TCPDF might be the best option, though it requires more manual setup.

Choose a tool that best fits your requirements in terms of HTML/CSS complexity, performance, and ease of use.