librepdf

LibreOffice, stripped and bundled for Node.js. Converts .docx, .html, and .txt to PDF — no Docker, no Gotenberg, no sidecar process to manage.

Note: Most of this project was done with AI assistance.

Install

npm install librepdf

Node.js 20+ required. Linux x86_64 only.

Usage

import { convert } from 'librepdf';
import { readFileSync } from 'fs';

const pdf = await convert(readFileSync('report.docx'));
// returns a Buffer

Options

// Override format detection
const pdf = await convert(input, { from: 'html' });

// Inject fonts at runtime (.ttf/.otf files or directories)
const pdf = await convert(input, { fonts: '/path/to/fonts/' });
const pdf = await convert(input, { fonts: ['/path/to/fonts/', '/path/to/custom.ttf'] });

from — one of docx, html, txt. Only needed if auto-detection gets it wrong.

fonts — path(s) to .ttf/.otf files or directories. Copied into LO's font directory before conversion; fontconfig picks them up automatically.

How it works

A stripped LibreOffice 26.2.4.2 installation is bundled. On the first call it decompresses to /tmp/instdir, then subsequent calls reuse that. Conversion runs soffice --headless --convert-to pdf and returns the PDF as a Buffer. Calc and Impress are stripped — only Writer is included.

Caveats

Fonts — Liberation fonts are not included (--without-fonts). THSarabunNew (GPL 2.0 + font exception) is bundled. To add more fonts permanently, drop .ttf/.otf files into ./fonts/ before building. For one-off injection, use the fonts runtime option.

Locales — Only en_US and th_TH locale data is bundled. ICU data and numbering rules for other locales are stripped (~35 MB savings). Locale-sensitive date/number formatting outside those two regions may not render correctly.

Build from source

git clone https://github.com/winth03/librepdf
cd librepdf
docker compose run --rm build   # produces lo.tar.br
npm run build                   # compiles src/ → dist/

License

MIT