# 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.

Page: https://developers.zactonz.com/guides/render-html-to-pdf/

Generating PDFs in PHP usually means bundling a headless browser or a heavyweight library. The [Screenshot (HTML)](https://developers.zactonz.com/apis/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
<?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.

```php
$ch = curl_init('https://api.zactonz.com/screen/html/');
curl_setopt_array($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.

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

To send it straight to the browser instead:

```php
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)](https://developers.zactonz.com/apis/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.