Render HTML to PDF with the Screenshot API

Turn an invoice, report or certificate template into a PDF from PHP, with no headless browser on your own server.

Generating PDFs in PHP usually means bundling a headless browser or a heavyweight library. The Screenshot (HTML) endpoint does the rendering for you: send a complete HTML document, ask for format=pdf, and get back the URL of the finished file.

1. Build the document#

The endpoint renders exactly what you send, in isolation. Two rules follow from that:

Use absolute URLs for images, fonts and stylesheets. Relative paths will not resolve.
Inline the CSS you care about. External stylesheets work if they are reachable over HTTPS, but inline styles remove a failure mode.

<?php
$html = <<<HTML
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <style>
    body { font-family: Helvetica, Arial, sans-serif; color: #171717; margin: 40px; }
    h1 { font-size: 24px; margin: 0 0 8px; }
    table { width: 100%; border-collapse: collapse; margin-top: 24px; }
    th, td { text-align: left; padding: 8px 0; border-bottom: 1px solid #e6e4e1; }
    .total { font-weight: bold; }
  </style>
</head>
<body>
  <h1>Invoice #1042</h1>
  <p>Issued 15 September 2026</p>
  <table>
    <tr><th>Item</th><th>Qty</th><th>Amount</th></tr>
    <tr><td>Design retainer</td><td>1</td><td>$1,200.00</td></tr>
    <tr class="total"><td>Total</td><td></td><td>$1,200.00</td></tr>
  </table>
</body>
</html>
HTML;

2. Send it#

Post the document as a form field. Rendering takes a few seconds, so give cURL a generous timeout.

$ch = curl_init('https://api.zactonz.com/screen/html/');
curl_setopt_array($ch, [
    CURLOPT_POST           => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TIMEOUT        => 90,
    CURLOPT_POSTFIELDS     => http_build_query([
        'html'   => $html,
        'format' => 'pdf',
    ]),
]);
$result = json_decode(curl_exec($ch), true);

if ((int) ($result['status'] ?? 0) !== 200) {
    throw new RuntimeException('Render failed: ' . ($result['data'] ?? 'no response'));
}
$pdfUrl = $result['data'];

3. Store or forward the file#

data is a URL on the API host. Fetch it and keep your own copy; that way your application does not depend on the capture staying available.

file_put_contents('/var/app/invoices/1042.pdf', file_get_contents($pdfUrl));

To send it straight to the browser instead:

header('Content-Type: application/pdf');
header('Content-Disposition: attachment; filename="invoice-1042.pdf"');
readfile($pdfUrl);

Page size and margins#

The HTML endpoint prints with Chromium's defaults. If you need control over paper size, orientation or margins, host the document at a URL and use Screenshot (URL) instead, which accepts paperWidth, paperHeight, orientation, margin* and scale for PDF output.

Images instead of PDFs#

The same request with format=png or format=jpeg returns a raster capture at the requested width and height. That is handy for social-share cards and email-safe previews of the same template.