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Common Use Cases & Examples

Explore real-world scenarios and code examples for the most common PDF processing tasks.

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Getting Started Authentication Use Cases Best Practices Migration (v1 → v2) Claude MCP Server (EN) Claude MCP Server (NL)

Workflow IDs

All examples use placeholder workflow IDs. Use GET /api/v2/user/workflows to find the correct IDs for your account.

Bulk Document Conversion

Convert multiple files in a single API call using async processing. Upload up to 50 files per request. When multiple files are processed with a convert workflow, the result is a ZIP archive containing individual PDFs.

cURL

# Upload multiple files at once
curl -X POST https://pdfen.com/api/v2/convert \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -F "files[]=@report1.docx" \
  -F "files[]=@report2.docx" \
  -F "files[]=@report3.docx" \
  -F "workflow_id=1" \
  -F "async=true"

PHP - Async with polling

<?php
$token = 'YOUR_API_TOKEN';
$files = ['report1.docx', 'report2.docx', 'report3.docx'];

// 1. Start async conversion
$postFields = ['workflow_id' => 1, 'async' => 'true'];
foreach ($files as $file) {
    $postFields['files[]'] = new CURLFile($file);
}

$ch = curl_init('https://pdfen.com/api/v2/convert');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => ["Authorization: Bearer $token"],
    CURLOPT_POSTFIELDS => $postFields,
]);
$result = json_decode(curl_exec($ch), true);
curl_close($ch);

$statusUrl = $result['status_url'];

// 2. Poll until done
do {
    sleep(2);
    $ch = curl_init($statusUrl);
    curl_setopt_array($ch, [
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_HTTPHEADER => ["Authorization: Bearer $token"],
    ]);
    $status = json_decode(curl_exec($ch), true);
    curl_close($ch);
} while ($status['status'] === 'processing' || $status['status'] === 'pending');

// 3. Download result (ZIP for multiple files, PDF for single file)
if ($status['status'] === 'done') {
    $ch = curl_init($status['download_url']);
    curl_setopt_array($ch, [
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_HTTPHEADER => ["Authorization: Bearer $token"],
    ]);
    file_put_contents('results.zip', curl_exec($ch));
    curl_close($ch);
}

OCR Processing

Add a searchable text layer to scanned PDFs. Use the options[ocr] and options[ocr_language] parameters to enable OCR.

cURL

curl -X POST https://pdfen.com/api/v2/convert \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -F "files[]=@scanned-document.pdf" \
  -F "workflow_id=1" \
  -F "options[ocr]=true" \
  -F "options[ocr_language]=eng" \
  -F "async=false"

PHP

<?php
$ch = curl_init('https://pdfen.com/api/v2/convert');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_TOKEN'],
    CURLOPT_POSTFIELDS => [
        'files[]' => new CURLFile('scanned-document.pdf'),
        'workflow_id' => 1,
        'options[ocr]' => 'true',
        'options[ocr_language]' => 'eng',
        'async' => 'false',
    ],
]);
$result = json_decode(curl_exec($ch), true);
curl_close($ch);

// Sync mode: download_url is immediately available
$ch = curl_init($result['download_url']);
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_TOKEN'],
]);
file_put_contents('ocr-result.pdf', curl_exec($ch));
curl_close($ch);

Supported OCR languages

eng (English), deu (German), nld (Dutch), fra (French), spa (Spanish), ita (Italian), por (Portuguese)

PDF Compression

Reduce PDF file size using different compression levels. Use the "Compress PDF" workflow with the options[compression] parameter.

cURL

curl -X POST https://pdfen.com/api/v2/convert \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -F "files[]=@large-document.pdf" \
  -F "workflow_id=1" \
  -F "options[compression]=web" \
  -F "async=false"

PHP

<?php
$ch = curl_init('https://pdfen.com/api/v2/convert');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_TOKEN'],
    CURLOPT_POSTFIELDS => [
        'files[]' => new CURLFile('large-document.pdf'),
        'workflow_id' => 1,
        'options[compression]' => 'web',
        'async' => 'false',
    ],
]);
$result = json_decode(curl_exec($ch), true);
curl_close($ch);

echo "Original: " . filesize('large-document.pdf') . " bytes\n";
echo "Compressed: " . $result['output_file_size'] . " bytes\n";

Compression levels

  • web — Optimized for screen viewing (good balance)
  • print — Optimized for printing (higher quality)
  • small — Maximum compression (smallest file size)
  • none — No compression

Email to PDF

Convert email files (.eml, .msg) to PDF. Attachments are included in the converted output. Use the "Convert Email to PDF" workflow.

cURL

curl -X POST https://pdfen.com/api/v2/convert \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -F "files[]=@message.eml" \
  -F "workflow_id=1" \
  -F "async=false"

PHP - Multiple emails

<?php
// Convert multiple email files at once
$ch = curl_init('https://pdfen.com/api/v2/convert');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_TOKEN'],
    CURLOPT_POSTFIELDS => [
        'files[0]' => new CURLFile('email1.eml'),
        'files[1]' => new CURLFile('email2.msg'),
        'workflow_id' => 1,
        'async' => 'true',
    ],
]);
$result = json_decode(curl_exec($ch), true);
curl_close($ch);

echo "Execution ID: " . $result['execution_id'] . "\n";
echo "Poll status at: " . $result['status_url'] . "\n";

Supported formats: .eml (standard email), .msg (Outlook email). For PST archives, use the "Convert PST to PDF" workflow.

Merge Multiple Files

Merge multiple PDF files into a single document. Use the "Merge PDFs" workflow. You can control the order of files with the file_order parameter.

cURL

curl -X POST https://pdfen.com/api/v2/convert \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -F "files[]=@chapter1.pdf" \
  -F "files[]=@chapter2.pdf" \
  -F "files[]=@chapter3.pdf" \
  -F "workflow_id=1" \
  -F 'file_order=["chapter1.pdf","chapter2.pdf","chapter3.pdf"]' \
  -F "async=false"

PHP

<?php
$ch = curl_init('https://pdfen.com/api/v2/convert');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_TOKEN'],
    CURLOPT_POSTFIELDS => [
        'files[0]' => new CURLFile('chapter1.pdf'),
        'files[1]' => new CURLFile('chapter2.pdf'),
        'files[2]' => new CURLFile('chapter3.pdf'),
        'workflow_id' => 1,
        'file_order' => json_encode(['chapter1.pdf', 'chapter2.pdf', 'chapter3.pdf']),
        'async' => 'false',
    ],
]);
$result = json_decode(curl_exec($ch), true);
curl_close($ch);

// Download the merged PDF
$ch = curl_init($result['download_url']);
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_TOKEN'],
]);
file_put_contents('merged.pdf', curl_exec($ch));
curl_close($ch);

Merge non-PDF files

You can also merge Word, Excel, or PowerPoint files into a single PDF. Use the appropriate merge workflow (e.g., "Merge Word to PDF") to convert and merge in one step.