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How to generate a PDF from HTML in PHP

Call the Inkspan /v1/generate/html endpoint from PHP to generate a PDF from HTML — no headless browser, font stack, or rendering infrastructure in your deploy. Keep your API key in the environment and POST.

Set CURLOPT_RETURNTRANSFER so the body comes back as a string rather than printing. Always check the HTTP status before writing the file.

PHP example

<?php
$ch = curl_init('https://api.inkspan.dev/v1/generate/html');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'X-API-Key: ' . getenv('INKSPAN_KEY'),
        'Content-Type: application/json',
    ],
    CURLOPT_POSTFIELDS => '{"html": "<h1>Invoice</h1>"}',
]);

$body = curl_exec($ch);
$code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
if ($code !== 200) { throw new Exception($body); }
file_put_contents('out.pdf', $body);

Request parameters

Name	Type	Required	Description
`html`	string	yes	The HTML document or fragment to render.
`filename`	string	no	Filename in the response's Content-Disposition. Defaults to `document.pdf`.

Response

Returns a PDF as a binary stream with Content-Type: application/pdf and Content-Disposition: attachment; filename=document.pdf. Write the response body straight to disk — do not parse it as JSON.

Production notes

Read the key with getenv() rather than hardcoding it, and keep it out of version control.

Relative URLs have no base to resolve against. Reference images and stylesheets with absolute https:// URLs, or inline them as data: URIs.
Page size and margins come from CSS, not from a parameter. Set @page { size: A4; margin: 18mm; } in your HTML to control them.
External resources are fetched server-side with SSRF protection, so private-network and file:// URLs are rejected. Host assets publicly or inline them.

Errors

Status	Meaning	Fix
`401`	Invalid or missing API key	Send your key in the `X-API-Key` header.
`402`	Monthly quota exceeded	The response reports used/quota. Upgrade at inkspan.dev/#pricing.
`422`	Missing or invalid parameter	Check required fields in the table above — the body names the offending field.

Failed requests do not count against your quota; only successful ones are metered.

Get a free API key →

Same operation in cURL · Python · Node.js · Other frameworks: Next.js · Django · Laravel · Ruby on Rails · All guides