PDF Attachment Extractor

How to use the pdf attachment extractor

1. Choose a PDF.
2. Review the attachments it carries, with their sizes and descriptions.
3. Save any of them.

About this tool

A PDF can carry whole files inside it, and nothing on the page says so. They are stored compressed in the document's own name tree rather than on any page, which is why attachments are so easy to overlook — and why a PDF you are forwarding may be carrying more than the pages you have read.

The most common case now is an electronic invoice. The ZUGFeRD and Factur-X standards work exactly this way: a human-readable invoice on the page with the machine-readable XML attached inside the same file, so one document serves both a person and an accounting system. Pulling that XML out is often the whole reason to use a tool like this.

Attachments are usually Flate-compressed, so extraction means inflating them. That is done with the browser's own decompression, the same mechanism the site already uses for gzip, and the extracted bytes are exact — a text attachment round-trips character for character and a binary one byte for byte, which is asserted directly.

The name is read from the document as stored, which matters because PDF names are frequently held as UTF-16 rather than plain text. A tool that assumes ASCII produces filenames with nulls scattered through them, and that is the usual symptom of this being done carelessly.

Common uses

• Pulling the XML out of an electronic invoice.
• Recovering a file someone attached to a PDF rather than sending separately.
• Checking what a PDF is carrying before forwarding it.

Frequently asked questions

What kind of files can a PDF contain?

Any kind. Attachments are arbitrary embedded files — spreadsheets, XML invoices, other PDFs — stored in the document structure rather than on a page.

What is ZUGFeRD or Factur-X?

Electronic invoice standards that put a readable invoice on the page and the machine-readable XML inside the same PDF as an attachment. This extracts that XML.

Are attachments the same as images in the document?

No. Images are page content; attachments are separate files carried along with it and are not visible on any page.