Building a Document Previewer: Extract PDF First Page as a Thumbnail

Here's how simple it is to extract the first page from any PDF. This code snippet demonstrates the core functionality:

<?php
$ch = curl_init('https://apdf.io/api/pdf/page/extract');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'Authorization: Bearer YOUR_API_TOKEN',
    'Accept: application/json',
    'Content-Type: application/json'
]);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode([
    'file' => 'https://example.com/large-report.pdf',
    'pages' => '1'
]));

$response = curl_exec($ch);
curl_close($ch);

$result = json_decode($response, true);
echo $result['file']; // URL to the 1-page preview PDF

That's it. Instead of downloading 50MB, your users now get a 50KB thumbnail that loads instantly.

Let's say you are building a corporate Document Management System. Your users upload contracts, proposals, and reports. The system stores the file URLs in a database, and when users browse the library, they see a grid of document cards.

Each card should show a preview of the first page, but the original PDFs are massive. Instead of showing a static placeholder icon, we'll dynamically generate a real preview by extracting Page 1.

Here's what we need:

1. Input: The URL of the full PDF stored in your system (e.g., AWS S3, database, file server).
2. Process: Send the URL to aPDF.io, request extraction of page 1.
3. Output: A lightweight preview PDF that can be displayed as a thumbnail.

1. Go to aPDF.io.
2. Sign up (it's free, no credit card required).
3. Copy your API Token from the dashboard.

This script demonstrates a full implementation. It takes a PDF URL, extracts the first page, and returns a download link for the preview.

<?php

// Configuration
$apiToken = 'YOUR_API_TOKEN_HERE';
$apiEndpoint = 'https://apdf.io/api/pdf/page/extract';

// Example: A large PDF stored in your system
$originalPdfUrl = 'https://ontheline.trincoll.edu/images/bookdown/sample-local-pdf.pdf';

// Extract only Page 1 for the preview
$requestData = [
    'file' => $originalPdfUrl,
    'pages' => '1'  // Only the first page
];

// Make the API request
$ch = curl_init($apiEndpoint);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'Authorization: Bearer ' . $apiToken,
    'Accept: application/json',
    'Content-Type: application/json'
]);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($requestData));

$response = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

// Handle the response
if ($httpCode === 200) {
    $result = json_decode($response, true);

    echo "✓ Preview PDF generated successfully!\\n";
    echo "Preview URL: " . $result['file'] . "\\n";
    echo "Pages: " . $result['pages'] . "\\n";
    echo "Size: " . number_format($result['size'] / 1024, 2) . " KB\\n";
    echo "\\n";
    echo "Note: This URL is valid for 1 hour.\\n";

    // In a real app, you would:
    // 1. Store this preview URL in your database
    // 2. Display it as a thumbnail in your UI
    // 3. Let users click it to view before downloading the full file

} else {
    echo "Error: " . $httpCode . "\\n";
    echo $response . "\\n";
}

Save the script as generate_preview.php and run it:

php generate_preview.php

✓ Preview PDF generated successfully!
Preview URL: https://apdf-files.s3.eu-central-1.amazonaws.com/abc123def456.pdf
Pages: 1
Size: 48.23 KB

Note: This URL is valid for 1 hour.

The original PDF was 3 pages and potentially large. The preview is now just 1 page and under 50KB, perfect for displaying as a thumbnail in your document library.

In a production DMS, you would typically:

1. On Upload: When a user uploads a PDF, immediately trigger the extraction of Page 1.
2. Store Preview URL: Save the preview URL in your database alongside the original file URL.
3. Display Thumbnails: In your document grid, show the preview PDF as an embedded thumbnail or image.
4. On Click: When users click the thumbnail, show a modal with the full document or download options.

Important: The preview URLs from the API are valid for 1 hour. If you need longer-lived previews, download the extracted PDF and store it in your own storage (S3, local filesystem, etc.).

Need more than just the first page? The API supports flexible page selection:

// Extract pages 1-3 for a longer preview
'pages' => '1-3'

// Extract specific pages
'pages' => '1,5,10'

// Extract first and last page
'pages' => '1,z'  // 'z' means the last page

• Faster Loading: Users see previews instantly without downloading full files.
• Reduced Bandwidth: Only transfer what's needed for the preview.
• Better UX: Users can verify documents before committing to a full download.
• No Server Processing: The API handles all the PDF manipulation, keeping your server lightweight.

Now that you can generate PDF previews, here are some related features to enhance your Document Management System:

• Search Inside Documents: Use the Search endpoint to let users find specific terms across all PDFs without downloading them.
• Extract Document Text: Use the Content Read endpoint to extract all text for full-text indexing or AI processing.