Attach a File Inside a PDF, Free
Attach any file inside a PDF so it travels with the document.
Select the PDF
Click to choose, or drop a file here
You can also paste (Ctrl+V / Cmd+V)
Most tools run entirely on your device
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About embedding a file in a PDF
PDF supports file attachments the same way an email does — one or more files stored inside the PDF's own structure, invisible on the page but available to anyone who opens the document in Acrobat or another reader with attachment support. It's a way to keep a source spreadsheet, a contract's supporting documents, or raw data alongside the PDF that references it, without sending several separate files.
This tool reads each file you add and stores it as a file attachment object inside the PDF's structure using pdf-lib, entirely in your browser. The attachment travels with the PDF from then on — copy or email the one file, and the attachments go with it. Not every PDF viewer surfaces attachments prominently, so if the recipient needs to be sure to find it, it's worth mentioning it's there.
Supported files
Accepts a PDF plus any file(s) to attach. Produces the same PDF with those files embedded inside it as attachments.
Is my file uploaded?
No. Both the PDF and the files you attach are processed entirely in your browser with pdf-lib — nothing is uploaded to a server.
How to Embed File in PDF
- 1
Select the PDF
Drop in the PDF that will carry the attachments.
- 2
Add files to attach
Pick any files — spreadsheets, images, source data, anything.
- 3
Embed and download
The files travel inside the PDF.
Embed File in PDF — frequently asked questions
Who can open the attachments?+
Any reader that supports PDF attachments — Acrobat, Preview, and the Extract Embedded Files tool here.
Does this increase the file size?+
Yes — the attachment bytes are stored in full inside the PDF.
Is there a free way to attach a file inside a PDF?+
Yes — this tool attaches the file entirely in your browser, free and with nothing uploaded.
Can I attach more than one file?+
Yes — add as many files as you need; they're all embedded in the same PDF.
Do you upload my files to a server?+
No — every tool here processes your files entirely on your device, and nothing is uploaded to a server. The only exception is the AI tools, which send the extracted text (not the file) to Claude to do their work.
Is there a file size limit?+
There's no artificial limit we impose, but since processing happens in your browser, very large files (500+ MB or 1,000+ pages) are limited by your device's memory rather than by us.
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