How to Add Attachments Inside a PDF (Files, Spreadsheets, Images)

Embed supporting files — spreadsheets, images, original source documents — directly inside a PDF for self-contained delivery.

3 min readAdd attachments

You're sending a final report, but the audit team also needs the raw spreadsheet, the methodology document, and the source CSV. Three separate files in an email feels messy.

PDFs can carry attachments inside them. The reader sees one file, but it contains everything — and recipients can extract the embedded files with a click.

Decide what to embed

Good candidates: the source spreadsheet behind a financial summary, the original Word document, raw images, supporting CSVs, related contracts.

Bad candidates: enormous video files (PDFs balloon fast), confidential material you don't want bundled, or anything the recipient should download separately for security reasons.

Attach files to the PDF

Open the PDF in Flint's editor and use the Attachments panel. Add each file — the panel shows file name and size. The PDF gets larger with each attachment, so check the final size before sending.

If size matters, consider compressing attachments before embedding them, or sending separately.

Tell readers the attachments exist

Half the trick is making sure readers know there are attachments. Many readers don't open the attachment pane by default. Add a note on the cover page or in the introduction: "This PDF includes embedded attachments — open the paperclip icon to view."

If you're sending to a non-technical audience, consider merging the supporting documents into the body instead. Embedded files are powerful but easy to miss.

FAQ

What file types can I embed?

Anything. Spreadsheets, Word docs, images, CSVs, even other PDFs. PDF readers handle the extraction — they save the embedded file back out to disk when the user clicks it.

Will the PDF size balloon?

Yes — the embedded file is added to the PDF byte for byte. A 5 MB spreadsheet adds 5 MB. Compress the attachments first if size is tight.

Can every PDF reader extract attachments?

Most do, with a paperclip or attachments icon. Some lightweight mobile readers hide them. Adobe Reader, Preview, Chrome's viewer, and Foxit all handle them properly.

Are embedded attachments encrypted?

Only if you password-protect the whole PDF. Protect the file and the attachments inherit the same protection.

Embedded attachments make a PDF self-contained — one file, all the context. Open yours in the editor and bundle the supporting material inside.

Try it now

Drop a PDF in and you'll be done in seconds — no install, files private to your account.

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How to Add Attachments to a PDF | Flint — Flint PDF