How to sanitize a PDF before sending it on a Mac
By Himanshu Ranjan · Updated 8 November 2026
To sanitize a PDF on a Mac, select it and run Sign & Lock › Sanitize for sending… in FileDial. It removes scripts, actions, attachments, comments and metadata and writes a fresh file with no old revisions. It does not hide visible text, so redact separately. It runs offline.
What hides inside a PDF
A PDF can carry more than the pages you see. Adobe's documentation notes that PDFs may contain hidden information such as metadata, comments, hidden layers and other content you may not want to share. In practice that means the author and software names, your review comments and sticky notes, embedded attachments, scripts and actions that run when the file opens, and earlier versions of the file left behind by incremental saves.
Data sanitization in general means removing sensitive data so that it cannot be recovered. For a PDF headed to a client, a court, a regulator or the public, a short sanitizing step avoids sending things you did not intend to.
Sanitize with FileDial
Work on a copy, and open the result before you send it.
- Select the PDF in Finder.
- Hold the right Option key to open the dial and choose the Sign & Lock category.
- Release on Sign & Lock › Sanitize for sending…
- Open the fresh copy and scan it for anything you expected to still be there.
- Attach the sanitized copy and keep the original.
What it removes, and what it keeps
The tool's note says it removes scripts, actions, attachments, comments and metadata, and gives you a fresh file with no old revisions. That is a thorough clean for non-visible content. Visible content is untouched: the text on the page, images, and any black rectangles that you drew.
That last point is the one that catches people. Sanitizing is not redaction. If a name or number is visible on the page, or is merely covered by a drawn rectangle, sanitizing leaves it. For that, use Sign & Lock › Redact text…, then confirm with Sign & Lock › Check redactions, which writes a .txt report of text still hidden under black boxes.
- Removed: scripts, actions, attachments, comments, metadata, old revisions.
- Kept: everything visible on the pages.
- Not a substitute for redaction.
Related tools, and when to use which
Use Sign & Lock › Remove metadata when you only want the properties cleared, and Pages › Remove annotations when you only want comments and drawings gone while links and form fields stay. Use Sanitize for sending… when the file goes outside your organization and you want everything non-visible cleaned in one step. And use Sign & Lock › Inspect PDF first when you want to see what is inside before you decide.
If the file contains photos, remember that image metadata may be separate, and review it in the way described in our guide to removing location from photos.
Signing comes last. Sanitizing changes the file, so any digital signature added earlier would be broken. If you need to sign, sanitize, check and then sign: Sign & Lock › Sign with certificate… for a certificate signature, or Sign & Lock › Place signature… for an image signature. After signing, avoid further edits.
A worked example: a report going to a regulator
A compliance report passed through three reviewers who each left comments, and it began life as a template with the old author's name. Before it goes out, run Inspect PDF to see the story, run Sanitize for sending…, then open the result: comments gone, properties blank, no attachments.
Then do the visible check. Search the PDF for words that should not be there, such as internal project names, and look at headers and footers. Sanitizing has no way to know that a project name on page 12 is private. If any appear, redact them on the sanitized copy, or fix the source and export again, then sanitize once more. Keep the commented original in your own files so the review history is not lost.
Common mistakes
Sanitizing and then sending the wrong file is common; name the sanitized copy clearly so you attach the right one. Another mistake is assuming sanitized means private: the visible content is still all there. A third is sanitizing a signed contract that must keep its signature intact; sanitize earlier in the process or accept that the signature will break. And a fourth is skipping the check. Open the finished file, search it, and look at it as the recipient will.
Honest alternatives
Adobe Acrobat has a Sanitize document option in its Redact tools, which removes hidden information, with options to choose what to remove. It is paid software. On a Mac without it, a local sanitizing tool covers the common cases. Printing the PDF to a new PDF through the print dialog creates a fresh file, but it can lose bookmarks and links, and we cannot say exactly what it drops, so check the result.
The point of sanitizing is to control what leaves your hands. Sending the file to an online tool to be sanitized defeats the purpose. FileDial does it locally.
Questions
What does sanitizing a PDF remove?
FileDial's Sanitize for sending… removes scripts, actions, attachments, comments and metadata, and writes a fresh file with no old revisions. It leaves visible page content alone, so it is not a substitute for redaction when text itself must go. Check the result before relying on it.
Is sanitizing the same as redacting?
No. Sanitizing cleans hidden, non-visible data. Redaction removes visible text or images that you must not share. Use Sign & Lock › Redact text… for that, then verify with Check redactions, because covering text with a black box alone does not remove it.
Should I sanitize before signing a PDF?
Yes. Sanitizing changes the file, so a digital signature made before it would show as broken. Finalize the pages, sanitize, check the result and then sign. Avoid editing the file after signing, because any later change breaks the signature. Check the result before relying on it.