Flatten PDFs

Flattening turns interactive elements (form fields, annotations) into static content so the document looks the same everywhere and cannot be edited.

import { PDFEngines } from "chromiumly";

const buffer = await PDFEngines.flatten([
  "path/to/file_1.pdf",
  "path/to/file_2.pdf",
]);

Returns a single PDF buffer. downloadFrom, webhook, outputFilename, and trace are also accepted — see Request tracing. Chromium converters and LibreOffice.convert() also accept a top-level flatten: true option to flatten the resulting PDF’s form fields and annotations in the same request. It’s a separate field from split there — see the note in Split PDFs. On the dedicated PDFEngines.split() route, flatten nests inside options instead.

Getting started

Chromium

LibreOffice

PDF engines

Advanced