← HTML to PDF

Convert HTML to PDF in PHP

Turn HTML and CSS into a PDF: invoices, receipts, reports, tickets. Rendered by Chromium, so modern CSS (flexbox, grid, web fonts) works. Here is the whole call in PHP, with the output it produced when we ran it.

Before you start

• An API key. Create a free account; it comes with free tokens every month. Put the key in an environment variable so it stays out of your code: export BLOODWEB_KEY=your_key
• PHP 7.4 or later with the curl extension, which most installs have.
• The input file in the same folder: invoice.html. Use your own; that is the name the code expects.

The code

Save it as html-to-pdf.php and run php html-to-pdf.php.

<?php
$ch = curl_init('https://bloodweb.net/api/v1/html-to-pdf');
curl_setopt_array($ch, [
    CURLOPT_POST           => true,
    CURLOPT_HTTPHEADER     => ['Authorization: Bearer ' . getenv('BLOODWEB_KEY')],
    CURLOPT_POSTFIELDS     => http_build_query(['html' => file_get_contents('invoice.html'), 'format' => 'A4']),
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TIMEOUT        => 120,
]);
$body   = curl_exec($ch);
$status = curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
if ($body === false) {
    exit(curl_error($ch) . "\n");
}
if ($status !== 200) {
    exit($status . ': ' . json_decode($body, true)['error']['message'] . "\n");
}
file_put_contents('invoice.pdf', $body);

What you get

Tested 19 October 2026: this exact code ran against our test copy of the API, which runs the same service code as bloodweb.net, and produced this.

It writes invoice.pdf: a PDF, 1 page, 24 KB.

Change the call

Every option the HTML to PDF takes. Add or change them the same way as the ones in the code.

• html: The HTML. It must be self-contained: inline <style>, and images and fonts as data: URIs. Remote files and scripts are not loaded.
• format: Paper size. When format, landscape and margin are all left out, the page's own CSS @page rule decides. One of: A3, A4, A5, Letter, Legal, Tabloid.
• landscape: Landscape orientation.
• margin: Page margin in millimetres.
• background: Print background colours and images.
• page_numbers: Print "Page 1 of 3" at the bottom centre of every page.

If it fails

A failed call is not charged. The answer is JSON with an error object; the code above prints its message. The usual ones:

• 401 missing_key or invalid_key: BLOODWEB_KEY is not set in the shell that runs the code, or the key was revoked.
• 400 bad_param: a value is wrong or missing. The message names the parameter.
• 402 insufficient_tokens: the balance does not cover the call. Top up in the dashboard.
• 429 rate_limited: too many calls at once. Wait the seconds in the Retry-After header and send it again.

Every code and its fix is in the docs.

Next

• The HTML to PDF page: every option, the limits, and Try it now in your browser.
• Getting started: keys, errors and rate limits for all the services.