API documentation

One endpoint: POST https://html-to-pdf.eu/v1/pdf. Send JSON, get a PDF. Nothing is stored.

Authentication

Create an API key in your dashboard. Keys start with h2p_ and are shown once. Send the key in the header Authorization: Bearer h2p_.... Keys in the query string (?apiKey=) are rejected with 401.

Quick start

curl

curl -X POST https://html-to-pdf.eu/v1/pdf \
  -H "Authorization: Bearer $H2P_KEY" \
  -H "Content-Type: application/json" \
  -d '{"html": "<h1>Hello</h1><p>My first PDF.</p>", "fileName": "hello"}' \
  -o hello.pdf

C# (HttpClient)

using System.Net.Http.Json;

using var http = new HttpClient { BaseAddress = new Uri("https://html-to-pdf.eu") };
http.DefaultRequestHeaders.Authorization =
    new("Bearer", Environment.GetEnvironmentVariable("H2P_KEY"));

var response = await http.PostAsJsonAsync("/v1/pdf", new
{
    html = "<h1>Hello</h1><p>My first PDF.</p>",
    format = "A4",
});
response.EnsureSuccessStatusCode();
await File.WriteAllBytesAsync("hello.pdf", await response.Content.ReadAsByteArrayAsync());
Console.WriteLine(response.Headers.GetValues("X-Credits-Remaining").First());

Node (fetch)

import { writeFile } from "node:fs/promises";

const response = await fetch("https://html-to-pdf.eu/v1/pdf", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.H2P_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({ html: "<h1>Hello</h1><p>My first PDF.</p>" }),
});
if (!response.ok) throw new Error(JSON.stringify(await response.json()));
await writeFile("hello.pdf", Buffer.from(await response.arrayBuffer()));
console.log(response.headers.get("X-Credits-Remaining"));

Request body

Content type application/json. Provide either html or url.

Field	Type	Default	Description
`html`	string		The HTML to render. Either `html` or `url` is required.
`url`	string		A public http or https URL on port 80 or 443 to render instead of `html`.
`headerHtml`	string		Header template, see below.
`footerHtml`	string		Footer template, see below.
`format`	string	`A4`	`A3`, `A4`, `A5`, `Letter` or `Legal`.
`landscape`	boolean	`false`	Landscape orientation.
`margin`	object		`{ "top", "right", "bottom", "left" }` as CSS lengths in `mm`, `cm`, `in` or `px`, for example `"15mm"`.
`printBackground`	boolean	`true`	Print background colours and images.
`scale`	number	`1`	Page scale from 0.1 to 2.
`waitFor`	string	`load`	`load` or `networkidle`: when the page counts as ready.
`delayMs`	integer	`0`	Extra wait after that, 0 to 5000 ms.
`fileName`	string		Download name, up to 200 characters, sent in `Content-Disposition`. `.pdf` is added when missing.

Headers and footers

Header and footer templates are only visible when the margin leaves room for them. With the default margin they may not show at all, so set margin.top and margin.bottom to at least 15mm when you use them. The templates can contain the classes pageNumber, totalPages, date and title, and need an explicit font size.

{
  "html": "<h1>Invoice 2026-001</h1>",
  "margin": { "top": "20mm", "bottom": "20mm", "left": "15mm", "right": "15mm" },
  "headerHtml": "<div style='font-size:9px;width:100%;text-align:center'>ACME B.V.</div>",
  "footerHtml": "<div style='font-size:9px;width:100%;text-align:center'>Page <span class='pageNumber'></span> of <span class='totalPages'></span></div>"
}

Response

On success: 200 with Content-Type: application/pdf and the PDF as the body, plus these headers:

X-Credits-Remaining: your balance after this render.
X-Pages: the number of pages in the PDF.

One successful PDF costs one credit. Failed renders cost nothing.

Errors

Errors are application/problem+json with a machine-readable code field.

Status	`code`	Meaning
400 / 415	`invalid_request`	Malformed JSON, or not `application/json`.
413	`invalid_request`	The raw request body is over 11 MB (twice the input limit plus 1 MB, room for JSON escaping).
401		Missing or unknown API key.
402	`no_credits`	Your credit balance is empty.
403		The account is blocked.
422	`invalid_request`	One or more fields are invalid; `errors` lists them.
422	`url_not_allowed`	The URL is not public http/https on port 80 or 443.
422	`too_many_pages`	The result would exceed 100 pages.
413	`output_too_large`	The generated PDF would exceed 25 MB.
429	`rate_limited`	Over 60 requests per minute for this key. `Retry-After` says when the window resets.
429	`busy`	Over 3 concurrent requests for the account, or the rendering service is at capacity. Comes with `Retry-After: 1`; retry after a second. Nothing is charged.
502	`target_unreachable`	The `url` could not be fetched.
503	`unavailable`	The renderer is temporarily unavailable. Nothing is charged.
504	`timeout`	Rendering took longer than 30 seconds.
500	`render_failed`	The render failed. Nothing is charged.

Limits

Input: 5 MB for html, headerHtml and footerHtml together (422 invalid_request). The raw JSON body is capped at 11 MB, twice the input limit plus 1 MB so escaped characters still fit (413).
Rendering time: 30 seconds.
Pages: 100 per PDF.
Output: 25 MB per PDF.
Concurrency: 3 requests at the same time per account.
Rate: 60 requests per minute per API key.

URLs

With url the page must be reachable on the public internet: http or https, port 80 or 443. Private networks, localhost and cloud-metadata addresses are refused. The same rule applies to everything the page loads while rendering. See how no storage works.