How to Convert HTML to PDF in PHP Using MPDF

Introduction

Generating PDF files from HTML content is essential for invoices, reports, contracts, and printable documents. MPDF is a powerful PHP library that allows us to convert HTML content—including CSS styles, images, and tables—into high-quality PDFs.

With MPDF, you can:

✅ Convert HTML pages into PDF dynamically
✅ Use CSS styling to format PDFs
✅ Include images, tables, and custom fonts
✅ Save, download, or email generated PDFs

By the end of this guide, you’ll be able to generate professional PDFs from HTML in PHP. 🚀

1. Installing MPDF in PHP

MPDF can be installed via Composer (recommended) or manually.

Install via Composer

composer require mpdf/mpdf

Include MPDF in Your PHP Script

require 'vendor/autoload.php';

use Mpdf\Mpdf;

✅ Now, MPDF is ready to generate PDFs from HTML!

2. Creating a Simple PDF from HTML

Let's generate a basic PDF with plain HTML content.

Example: Convert Simple HTML to PDF

require 'vendor/autoload.php';

use Mpdf\Mpdf;

$mpdf = new Mpdf();
$html = '<h1>Hello, MPDF!</h1><p>This is a simple PDF generated from HTML.</p>';

$mpdf->WriteHTML($html);
$mpdf->Output('simple.pdf', 'I');

Explanation:

✅ WriteHTML($html) – Converts HTML into a PDF.
✅ Output('simple.pdf', 'I') – Displays the PDF in the browser.

🔹 Change 'I' to 'D' to force a download:

$mpdf->Output('download.pdf', 'D');

3. Converting an External HTML File to PDF

Instead of embedding HTML, load it from an external file (e.g., invoice.html).

$html = file_get_contents('invoice.html');

$mpdf = new Mpdf();
$mpdf->WriteHTML($html);
$mpdf->Output('invoice.pdf', 'I');

✅ Works well for exporting webpages as PDFs.

4. Styling PDF with CSS (Tables, Fonts, Colors)

MPDF fully supports CSS, allowing us to format the document.

Example: Styled Invoice with CSS

$html = '
<style>
  body { font-family: Arial, sans-serif; }
  h1 { color: #333; text-align: center; }
  table { width: 100%; border-collapse: collapse; margin-top: 20px; }
  th, td { border: 1px solid #ddd; padding: 8px; text-align: left; }
  th { background-color: #f4f4f4; }
</style>

<h1>Invoice</h1>
<table>
  <tr><th>Item</th><th>Quantity</th><th>Price</th></tr>
  <tr><td>Product A</td><td>1</td><td>$100</td></tr>
  <tr><td>Product B</td><td>2</td><td>$50</td></tr>
</table>
';

$mpdf = new Mpdf();
$mpdf->WriteHTML($html);
$mpdf->Output('styled_invoice.pdf', 'I');

✅ Tables, fonts, and colors work just like in HTML & CSS.

🔹 Use @page CSS rules for custom margins and headers.

5. Adding Images to PDF

MPDF allows embedding logos, product images, and charts in PDFs.

Example: Add an Image to PDF

$html = '
<h1>Company Report</h1>
<img src="logo.png" width="150">
<p>Annual Performance Overview.</p>
';

$mpdf = new Mpdf();
$mpdf->WriteHTML($html);
$mpdf->Output('image_pdf.pdf', 'I');

✅ Supports PNG, JPEG, GIF, and SVG images.

🔹 Use full URLs (https://example.com/image.jpg) for external images.

6. Saving PDFs to the Server

To store generated PDFs, use file_put_contents().

$pdfOutput = $mpdf->Output('', 'S'); // Get PDF content as a string
file_put_contents('saved_pdfs/invoice.pdf', $pdfOutput);

✅ Useful for storing and processing PDFs later.

7. Emailing a PDF as an Attachment

MPDF works well with PHPMailer for emailing PDFs.

Example: Email a PDF Attachment

use PHPMailer\PHPMailer\PHPMailer;

$mail = new PHPMailer();
$mail->addAttachment('saved_pdfs/invoice.pdf');
$mail->send();

echo "PDF sent via email!";

✅ Automatically generates and emails PDF documents.

8. Adding Page Numbers and Headers

For multi-page PDFs, add headers, footers, and page numbers dynamically.

Example: Add Page Numbers to a PDF

$mpdf = new Mpdf();
$mpdf->SetFooter('Page {PAGENO} of {nbpg}');

$html = '<h1>Multi-Page Report</h1><p>Report content goes here...</p>';
$mpdf->WriteHTML($html);

$mpdf->Output('paged_report.pdf', 'I');

✅ Ensures professional document formatting.

9. Securing PDFs (Password Protection and Encryption)

To protect a PDF, apply a password and restrict permissions.

Example: Password-Protect a PDF

$mpdf->SetProtection(['copy', 'print'], 'userpassword', 'adminpassword');
$mpdf->Output('secure.pdf', 'I');

✅ Users must enter a password to open or print the PDF.

10. Converting Dynamic Web Pages to PDF

Capture dynamic webpage content and save it as a PDF.

Example: Convert a Live Webpage to PDF

$html = file_get_contents("https://example.com/report");
$mpdf->WriteHTML($html);
$mpdf->Output('webpage.pdf', 'I');

✅ Great for exporting reports, dashboards, and blog posts.

Best Practices for HTML to PDF Conversion in PHP

✔ Use inline CSS for best PDF rendering compatibility.
✔ Optimize images before adding them to PDFs.
✔ Use file_put_contents() to store PDFs on the server.
✔ Test PDF output on different devices and screen sizes.
✔ Secure sensitive PDFs with password protection.

Conclusion

With MPDF, you can easily convert HTML pages, invoices, reports, and receipts into PDF format while maintaining CSS styling, images, and tables.

✅ MPDF simplifies HTML-to-PDF conversion in PHP.
✅ Supports styling, images, tables, and dynamic content.
✅ Great for generating invoices, reports, and order receipts.

By following this guide, you can efficiently generate and process PDFs from HTML in your PHP applications! 🚀