Generate PDF in PHP (FPDF Invoice)

Making PDFs in PHP

PDFs are perfect for invoices, receipts, admit cards and reports — documents that must look the same everywhere and be easy to print. PHP does not create PDFs on its own, so we use a small, free library. Two popular choices are FPDF and Dompdf.

Why you need a library

There is no built-in PDF function in PHP, and building the PDF format by hand is very complex. A library handles all that for you. You install one with Composer:

composer require setasign/fpdf
// or
composer require dompdf/dompdf

Then you include Composer's autoloader and use the library's simple methods.

Creating a PDF with FPDF

FPDF lets you add text and shapes at exact positions.

<?php
  require "vendor/autoload.php";
  $pdf = new FPDF();
  $pdf->AddPage();
  $pdf->SetFont("Arial", "B", 16);
  $pdf->Cell(40, 10, "Invoice #1001");
  $pdf->Ln();
  $pdf->SetFont("Arial", "", 12);
  $pdf->Cell(40, 10, "Total: Rs 2500");
  $pdf->Output();   // show in browser
?>

AddPage starts a page, SetFont sets the font, Cell prints a box of text, and Output sends the PDF. It is ideal for precise, structured layouts.

HTML to PDF with Dompdf

If you already have HTML, Dompdf turns it straight into a PDF.

<?php
  require "vendor/autoload.php";
  use Dompdf\Dompdf;

  $dompdf = new Dompdf();
  $dompdf->loadHtml("<h1>Invoice #1001</h1><p>Total: Rs 2500</p>");
  $dompdf->render();
  $dompdf->stream("invoice.pdf");
?>

You write normal HTML and CSS, and Dompdf renders it as a PDF. This is great when you already have an HTML template for the document.

Common uses

• Invoices and receipts for orders and payments.
• Admit cards and certificates for schools and exams.
• Reports like sales summaries or attendance.
• Tickets and passes that users download and print.

Common mistakes

• Output before the PDF. A stray space or echo corrupts the file — output only the PDF.
• Expecting PHP to do it alone. You need a library like FPDF or Dompdf.
• Complex CSS in Dompdf. It supports common CSS, but very advanced layouts may not render perfectly.
• Not installing via Composer. Add the library properly and include the autoloader.

Summary

• PHP needs a library to create PDFs — FPDF or Dompdf.
• FPDF places text and shapes by position (precise control).
• Dompdf converts HTML/CSS into a PDF (familiar approach).
• Output with Output() (FPDF) or stream() (Dompdf), with no output before.
• Great for invoices, certificates, reports and tickets.

Next, pull the data from MySQL, or export it another way with CSV export.