Accessible PDF

Create accessible PDFs that work with screen readers and assistive technologies by using tagged structure, alternative text, and language tagging.

What Makes a PDF Accessible?

Requirement	Why It Matters
Structure tags	Screen readers use heading/paragraph/list tags for navigation
Alt text	Describes images to users who cannot see them
Language tag	Tells the reader how to pronounce text
Reading order	Logical order independent of visual layout
Table headers	Associates data cells with their column/row context
Bookmarks	Keyboard navigation for long documents

Standards

Standard	Scope
PDF/UA-2 (ISO 14289-2)	PDF Universal Accessibility
WCAG 2.1	Web Content Accessibility Guidelines
Section 508	US federal accessibility
EN 301 549	EU accessibility requirements

Full Code Example

<?php

declare(strict_types=1);

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

use TcpdfNext\Document;
use TcpdfNext\Enums\Alignment;
use TcpdfNext\Accessibility\TagManager;

// ── 1. Enable tagged PDF ───────────────────────────────────────────────
$pdf = Document::create()
    ->setTitle('Accessibility Report 2026')
    ->setAuthor('Acme Corp')
    ->setLanguage('en-US')
    ->setTagged(true)
    ->setDisplayDocTitle(true)
    ->addPage();

$tag = $pdf->getTagManager();

// ── 2. Heading (H1) ───────────────────────────────────────────────────
$tag->beginTag('H1');
$pdf->setFont('helvetica', style: 'B', size: 24)
    ->cell(0, 14, 'Accessibility Report 2026', newLine: true);
$tag->endTag();

// ── 3. Paragraph ──────────────────────────────────────────────────────
$tag->beginTag('P');
$pdf->setFont('times', size: 12)
    ->multiCell(0, 7, 'Acme Corp is committed to producing documents that '
        . 'meet PDF/UA and WCAG 2.1 AA standards, ensuring equal access '
        . 'for all users regardless of ability.');
$tag->endTag();

// ── 4. Sub-heading (H2) ──────────────────────────────────────────────
$tag->beginTag('H2');
$pdf->setFont('helvetica', style: 'B', size: 18)
    ->cell(0, 12, 'Key Metrics', newLine: true);
$tag->endTag();

// ── 5. Tagged list ────────────────────────────────────────────────────
$items = [
    'Documents audited: 1,240',
    'Compliance rate: 98.7%',
    'Issues resolved: 412',
];

$tag->beginTag('L');
foreach ($items as $item) {
    $tag->beginTag('LI');

    $tag->beginTag('Lbl');
    $pdf->setFont('helvetica', size: 11)
        ->cell(8, 7, "\u{2022}");
    $tag->endTag(); // Lbl

    $tag->beginTag('LBody');
    $pdf->cell(0, 7, $item, newLine: true);
    $tag->endTag(); // LBody

    $tag->endTag(); // LI
}
$tag->endTag(); // L

// ── 6. Image with alt text ────────────────────────────────────────────
$tag->beginTag('Figure');
$pdf->image(
    file:    __DIR__ . '/assets/compliance-chart.png',
    x:       null,
    y:       null,
    width:   120,
    height:  null,
    altText: 'Bar chart showing compliance rate rising from 91% in 2023 '
           . 'to 98.7% in 2026 across four consecutive years.',
);
$tag->beginTag('Caption');
$pdf->setFont('helvetica', style: 'I', size: 9)
    ->cell(0, 6, 'Figure 1: Compliance trend 2023-2026', newLine: true);
$tag->endTag(); // Caption
$tag->endTag(); // Figure

// ── 7. Decorative element as artifact (skipped by screen readers) ─────
$tag->beginArtifact('Layout');
$pdf->setDrawColor(200, 200, 200)
    ->line(15, $pdf->getY(), 195, $pdf->getY());
$tag->endArtifact();

// ── 8. Tagged table ───────────────────────────────────────────────────
$tag->beginTag('H2');
$pdf->setFont('helvetica', style: 'B', size: 18)
    ->cell(0, 12, 'Quarterly Results', newLine: true);
$tag->endTag();

$tag->beginTag('Table');

// Header row
$tag->beginTag('TR');
foreach (['Quarter', 'Audited', 'Passed', 'Rate'] as $header) {
    $tag->beginTag('TH', attributes: ['scope' => 'col']);
    $pdf->setFont('helvetica', style: 'B', size: 10)
        ->cell(45, 8, $header, border: 1);
    $tag->endTag();
}
$tag->endTag(); // TR

// Data rows
$rows = [
    ['Q1', '310', '305', '98.4%'],
    ['Q2', '320', '316', '98.8%'],
    ['Q3', '305', '302', '99.0%'],
    ['Q4', '305', '301', '98.7%'],
];
foreach ($rows as $row) {
    $tag->beginTag('TR');
    foreach ($row as $i => $cell) {
        $tagName = $i === 0 ? 'TH' : 'TD';
        $attrs   = $i === 0 ? ['scope' => 'row'] : [];
        $tag->beginTag($tagName, attributes: $attrs);
        $pdf->setFont('times', size: 10)
            ->cell(45, 8, $cell, border: 1);
        $tag->endTag();
    }
    $tag->endTag(); // TR
}
$tag->endTag(); // Table

// ── 9. Language tagging for foreign text ──────────────────────────────
$tag->beginTag('P', attributes: ['lang' => 'de-DE']);
$pdf->setFont('times', size: 11)
    ->multiCell(0, 7, 'Barrierefreiheit ist ein grundlegendes Recht.');
$tag->endTag();

// ── 10. Save ──────────────────────────────────────────────────────────
$pdf->save(__DIR__ . '/accessible-report.pdf');

echo 'Accessible PDF created.' . PHP_EOL;

HTML Auto-Tagging

TCPDF-Next can generate structure tags automatically from semantic HTML:

$pdf = Document::create()
    ->setTagged(true)
    ->setLanguage('en-US')
    ->addPage();

$pdf->setAutoTagging(true)
    ->writeHtml(<<<'HTML'
        <h1>Report</h1>
        <p>Summary paragraph.</p>
        <img src="chart.png" alt="Revenue chart showing 15% growth" />
        <table>
            <tr><th>Q</th><th>Revenue</th></tr>
            <tr><td>Q1</td><td>$548M</td></tr>
        </table>
    HTML);

HTML Element	PDF Tag
<h1>--<h6>	H1--H6
<p>	P
<img alt="...">	Figure
<table>	Table
<th>	TH
<td>	TD
<ul>, <ol>	L
<li>	LI
<a>	Link

Accessibility Checklist

• [ ] setTitle() -- document title is set
• [ ] setDisplayDocTitle(true) -- viewer shows title, not filename
• [ ] setLanguage('en-US') -- document language declared
• [ ] All content wrapped in structure tags
• [ ] Headings in sequential order (H1, H2, H3 -- no skips)
• [ ] All meaningful images have altText
• [ ] Decorative images marked as artifacts
• [ ] Tables have TH cells with scope attribute
• [ ] Reading order matches logical order
• [ ] Color contrast ratio at least 4.5:1

Validation

# Use PAC (PDF Accessibility Checker) for PDF/UA validation
# https://pdfua.foundation/en/pac-download/

Further Reading

• PDF/A-4 Archival -- combine accessibility with archival