← HTML to PDF

Convert HTML to PDF with curl

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 with curl, 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
curl 7.76 or later (for --fail-with-body, which makes curl stop on an error and still show the reason).
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.sh and run bash html-to-pdf.sh.

curl -sS --fail-with-body \
  -H "Authorization: Bearer $BLOODWEB_KEY" \
  --data-urlencode html@invoice.html \
  -d format=A4 \
  https://bloodweb.net/api/v1/html-to-pdf \
  -o invoice.pdf

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.

The HTML to PDF output, page 1 — Page 1 of the result.

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; curl stops with an error, and that JSON lands in invoice.pdf instead of the result, so open it as text to read the reason. 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401 missing_key or invalid_key: BLOODWEB_KEY is not set in the shell that runs the code, or the key was revoked.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.

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.