@formepdf/html

HTML + print-CSS to PDF on the Forme engine. No headless browser, no Chromium cold start — a Rust layout engine compiled to WASM, running wherever Node runs.

npx @formepdf/html invoice.html

const { renderHtml } = require('@formepdf/html');

const { pdf, warnings } = renderHtml(html, { pageSize: 'Letter' });
fs.writeFileSync('invoice.pdf', pdf);
warnings.forEach((w) => console.warn(w)); // everything outside the subset, named

What works

The paged-media CSS browsers took two decades to ship — and the parts they still haven't:

• @page: size (named or dimensions), margins, :first variants
• Margin boxes (@top-center, @bottom-right, ...): running headers/footers in the page margin, with content() strings and counter(page) / counter(pages)
• Break control: break-before/after/inside plus the legacy page-break-* spellings every wkhtmltopdf-era template still carries
• orphans / widows, <thead> repetition on every page
• Stylesheets with a documented selector subset, the full cascade with !important, flexbox, a CSS Grid subset, tables with colspan/rowspan, lists, images
• Floats as column rows — float: left/right + clear lay consecutive floated siblings out as a row (the Bootstrap col-* and left/right header-pair shape real templates use); only true text-wrapping alongside a float is out, and it warns

Measured against 15 real production templates from GitHub (Bootstrap 2/3 grids, mPDF/wkhtmltopdf-era tables, email HTML, modern CSS grid): 14 of 15 render correctly, the one degraded case is legible with its cause named in warnings, zero render broken (as of 0.20.0).

The complete property-by-property subset table lives in the repository README — everything outside it lands in warnings, never silently dropped.

CLI

forme-html <input.html> [-o out.pdf] [--css print.css]
           [--page-size Letter] [--margin 36] [-q]

CLI/API options override the document's @page rule, the way a print dialog overrides a stylesheet.