Optimize PDFs – Remove sensitive content and information by sanitising and redacting.

Knowing how to safeguard private, confidential, and sensitive information when you’re sharing documents electronically and online is essential. There are two ways to remove sensitive PDF content or private information from your PDF files — sanitizing and redacting. Read on to learn the difference between the two, and how to do each with Adobe Acrobat.

Image of a broom sweeping over and cleaning digital data belonging to individuals.

What you’ll learn

Why use PDFs?

Portable document files (PDFs) have been the go-to for sharing files electronically and online since the early 1990s. Adobe invented the PDF to be able to easily share files between different systems and devices without losing any formatting, or recipients needing anything other than the free Adobe Acrobat Reader to open and view documents.

Nowadays, PDFs have extensive layers of in-built security that you can select from and apply to protect your document contents. You can allow people to edit and review PDF files according to your needs. You can also create PDFs to be as dynamic and interactive for your users as you wish.

What is PDF sanitizing or redacting?

Potentially sensitive information may be found in your PDF document properties or the content itself. The data stored in documents is more than just the text you visually see on the pages. When you sanitize PDF files and/or redact a PDF, you remove information from the document so that it isn’t sent with your document and can’t be viewed by others. It’s an important PDF optimization process.

Why remove or redact information or content?

There are several reasons why you might want to remove or redact information from a PDF file when you optimize a PDF. These include —

Illustration of a cloud computing and filing sharing concept with icons depicting security, searching, email, file sharing, and compliance.

How to redact information from a PDF.

You can use the Redact Tool in Adobe Acrobat Pro to permanently remove text and images from your PDF files. The Redact feature in Acrobat blocks out text or images. Viewers of your document will not be able to see what you have redacted or use any PDF editing tools to see what was redacted.

Follow these step-by-step instructions to redact PDF text or images.

  1. Make a copy of your PDF.
    Create a copy of your PDF so you can revert to your original document if you need to.

  2. From the Tools, select Redact a PDF.
    Select Redact a PDF from the Tools menu. You’ll then see options to redact text and images, redact pages, find text to redact, and set redaction properties.

    Screenshot from Adobe Acrobat Pro showing the menu options in the Redact a PDF tool.

  3. Set your redaction properties.
    Click on the “Set properties” option to change the appearance of your redacted content. Here, you can change the fill and outline colour and add overlay text if you want to.

    Screenshot from Adobe Acrobat Pro showing the options to set the visual properties for redacted text and images.

  4. Select the text you want to redact.
    Select the text you want to redact, and then click apply. You will then be prompted to save your PDF as the same or a different file name with the word redacted automatically appended to the filename.

    Screenshot from Adobe Acrobat Pro showing redacted text in a PDF document.

How to sanitize and remove metadata from a PDF.

Use the Redact Tool in Adobe Acrobat Pro to permanently remove hidden PDF data and metadata from your PDF document. You can use this tool to selectively remove metadata or remove all metadata. This tool prevents any sensitive “hidden” information from being passed on when you share or publish your PDF.

Follow these step-by-step instructions to sanitize PDF documents.

  1. Make a copy of your PDF.
    Create a copy of your PDF so you can revert to your original document if you need to.

  2. From the Tools, select Redact a PDF.
    Select Redact a PDF from the Tools menu. You’ll then see the “Sanitize document” option at the bottom of the options.

  3. Choose whether to Selectively remove or Remove all hidden data.
    Decide whether you want to selectively remove or Remove all hidden data.

    Screenshot from Adobe Acrobat Pro showing the sanitize document options to selectively remove data or remove all data.

    • When you choose the “Selectively remove” option, Adobe Acrobat will first examine your document to remove hidden PDF data, and then display the results.
    • When you select “Remove all,” Adobe Acrobat will prompt you to save your file, and then remove sensitive content and compress your file at the same time.

Other ways to protect content and remove pages from PDFs.

There are a few other things you can do to protect and remove sensitive PDF content that you don’t want to share. These include —

Keep exploring! A few related articles on how to optimize PDFs and keep your information safe include —