What is a PDF attachment?

PDF files can carry embedded files inside the document itself. Those attachments can be anything from images and text files to spreadsheets or other PDFs.

Tool description

This tool opens a PDF, reads any attachments already stored inside it, and lets you add more files before downloading a new PDF. Existing attachments are shown under "Already in this PDF", while new files appear in a separate list so you can check what will be attached.

Features

  • Reads existing embedded attachments from a PDF
  • Lets you add new files and download a PDF with all attachments included
  • Keeps duplicate names separate with numbered file paths

How it works

The base PDF is parsed in the browser with PDF.js. Any existing attachments are listed in the tree view, then the selected files are attached with their file names, MIME types, and timestamps before the updated PDF is saved and downloaded.

Tips

  • If two files share the same name, the tool adds a number to keep both entries.
  • The file browser lets you review the resulting attachment tree before you export.
  • Use the original file name when you want the embedded attachment to be easy to recognize later.