Introduction
PDF (Portable Document Format) is widely used for creating documents that need to be shared, printed, or preserved in a fixed layout. In web development, generating PDFs dynamically can be crucial for reports, invoices, certificates, and other structured documents.
PHP offers several libraries to generate PDFs programmatically, each with its strengths and best use cases. In this article, we will explore some of the most popular PHP libraries for PDF generation, how to install and use them, and best practices for generating optimized PDFs.
Popular PHP Libraries for PDF Generation
Several PHP libraries can be used to generate PDFs, including:
- TCPDF – A popular and feature-rich library for generating PDFs in PHP.
- FPDF – A lightweight and simple-to-use PDF generation library.
- mPDF – A library based on FPDF with additional features and HTML/CSS support.
- Dompdf – A popular choice for generating PDFs from HTML and CSS.
- wkhtmltopdf – A command-line tool that converts HTML to PDF using the WebKit rendering engine.
1. TCPDF
Installation: You can install TCPDF using Composer:
composer require tecnickcom/tcpdf
Basic Example:
require_once('vendor/autoload.php');
$pdf = new TCPDF();
$pdf->AddPage();
$pdf->SetFont('Helvetica', '', 12);
$pdf->Cell(0, 10, 'Hello, this is a TCPDF example!', 0, 1, 'C');
$pdf->Output('example.pdf', 'D');
TCPDF supports images, barcodes, custom fonts, and more.
2. FPDF
Installation: Download FPDF from fpdf.org and include it in your project.
Basic Example:
require('fpdf.php');
$pdf = new FPDF();
$pdf->AddPage();
$pdf->SetFont('Arial', 'B', 16);
$pdf->Cell(40, 10, 'Hello, World!');
$pdf->Output();
3. mPDF
Installation:
composer require mpdf/mpdf
Basic Example:
require_once __DIR__ . '/vendor/autoload.php';
$mpdf = new \Mpdf\Mpdf();
$mpdf->WriteHTML('<h1>Hello World</h1>');
$mpdf->Output('example.pdf', 'D');
mPDF allows HTML-to-PDF conversion with CSS support.
4. Dompdf
Installation:
composer require dompdf/dompdf
Basic Example:
use Dompdf\Dompdf;
require 'vendor/autoload.php';
dompdf = new Dompdf();
$html = '<h1>Welcome to Dompdf</h1><p>This is an example PDF.</p>';
$dompdf->loadHtml($html);
$dompdf->render();
$dompdf->stream('example.pdf');
Dompdf supports HTML and CSS but may have limitations with complex layouts.
5. wkhtmltopdf
Installation:
sudo apt install wkhtmltopdf
Usage with PHP:
$html = '<html><body><h1>Hello, World!</h1></body></html>';
file_put_contents('temp.html', $html);
shell_exec('wkhtmltopdf temp.html output.pdf');
wkhtmltopdf is highly accurate in rendering HTML into PDFs but requires a system installation.
Best Practices for Generating PDFs in PHP
- Use Vector Graphics: PDFs often include images; using vector formats (SVG) ensures scalability.
- Optimize for Performance: Avoid large inline images; instead, link images from external sources.
- Use UTF-8 Encoding: Ensure proper text rendering, especially for non-Latin characters.
- Security Considerations: Sanitize user-generated input to prevent script injections.
- Test Across PDF Viewers: Ensure compatibility with different PDF readers.
Conclusion
Generating PDFs in PHP is straightforward with the right tools. Whether you need basic text-based PDFs or complex documents with HTML and CSS, there is a PHP library suited to your needs. Libraries like TCPDF, FPDF, and mPDF offer excellent features, while Dompdf and wkhtmltopdf are ideal for HTML-based PDF creation.
By following best practices and choosing the appropriate library, you can create professional and optimized PDFs for your applications.