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Check a PDF for hidden data before you send it

A PDF can carry more than its pages: the author’s name, earlier versions, attachments, review comments and text that is only covered by a black box. See what your file reveals, then download a cleaned copy. The check runs locally — the file is not uploaded anywhere.

Local browser processing — files stay in this browser

Check your PDF before you send it

The check and the clean-up run in this browser. PDFflow does not upload the document, its name or its contents to any server.

File limit
50.0 MB
Page limit
200 pages
Processing
This browser
No PDF selected yet.

By using this tool, you agree to the Terms of Use and acknowledge the Privacy Policy.

Current limits

  • One PDF per check
  • Maximum file size: 50 MB
  • Maximum pages: 200
  • Encrypted or password-protected PDFs are not supported

What the check looks for

Text hidden under black boxes

Drawing a black rectangle over text hides it on screen but leaves it in the file, where it can be selected and copied. The check finds text that renders as a solid box.

Earlier saved versions

Incremental saves keep the previous version of the document inside the same file. Deleted text can be recovered from it.

Attachments, scripts and comments

Embedded files, JavaScript, review notes and the names of the people who wrote them travel with the PDF unless they are removed.

Document properties

Author, title, editing software and dates are stored in the file and visible in any viewer’s properties dialog.

Personal data in the text

Email addresses, phone numbers, payment card numbers and IBANs are listed (masked) so you can confirm they are meant to be there.

Text outside the page and hidden layers

Content placed outside the visible area or in layers that are switched off is invisible but still part of the document.

How it works

  1. Choose one PDF under 50 MB and 200 pages.
  2. Read the report: each finding says why it matters and whether Clean PDF removes it.
  3. Press Clean PDF and download. The cleaned copy is checked again before you get it.

How files are handled

Your PDF is read, checked and cleaned directly in this browser. PDFflow does not upload the document, file name or page contents to its servers. Personal data found in the text is shown masked and is never stored.

Limitations

  • Encrypted and password-protected PDFs are not supported.
  • Hidden-text detection looks for text under dark boxes; text hidden in other ways, such as white text on a white page, may not be found.
  • Personal data is found by pattern; names and postal addresses are not detected in the current version.
  • Cleaning invalidates digital signatures and makes form fields static.

PDF privacy check FAQ

Is my PDF uploaded to check it?

No. The check and the clean-up run in your browser with the selected file. PDFflow does not send the PDF, its file name or its contents to any server.

How do I remove metadata from a PDF?

Choose the PDF, review the report, then press Clean PDF and download. The cleaned copy has no author, title, software or date properties, no XMP metadata packet and no earlier saved versions.

Why is text under a black box still a problem?

A box drawn on top of text only changes what is painted on screen. The characters stay in the page content, so they can be selected, copied, searched or extracted. Clean PDF fixes this by flattening those pages into images.

What does flattening a page do?

The page is replaced with an image of how it looks. Hidden text is gone for good, but text on that page can no longer be selected or searched. Only pages where hidden text was found are flattened.

Does Clean PDF remove names or numbers from the visible text?

No. Visible text is never changed. Personal data the check finds in the text is listed so you can decide what to do; to remove a page, use Delete PDF pages.

Will cleaning change how my document looks?

Pages keep their content and layout. Sticky notes and attachments are removed, interactive form fields become static, and layers that were switched off become visible so you can review them. A digital signature becomes invalid after any change.

Is the privacy check free?

Yes. The check and the cleaned download are free, with no account, sign-up or watermark.

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