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.
What you’ll learn
- Why PDF files are the go-to for sharing electronic documents
- What PDF sanitising and redacting is
- Why you might remove or redact information or content from a PDF
- How to redact content from a PDF
- How to remove metadata from a PDF
- Other ways to protect content and remove pages from PDFs
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.
- Sanitize document properties metadata.
Electronic documents of all types usually contain a range of metadata or information that gets added to the properties of a file. Document properties can be added manually, while some of it is automatically generated as a document is worked on.
Metadata is traceable and serves various purposes, including document organization, searchability, and ensuring proper attribution and credit to the document's author/owner. For example, Metadata such as keywords and subjects can be used for indexing and categorizing PDFs in document management systems.
- Redact sensitive document information and contents.
Documents also often contain a range of personal and confidential information that should redacted to prevent unauthorised viewing. This might include any personal identification information that could lead to potential identity theft, such as dates of birth, credit card numbers, and addresses. In commercial documents and contracts, this might include commercially sensitive financial information and details on non-disclosure.
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 —
- Traceability.
Metadata can contain sensitive information about the document creators or editors. Removing metadata can help protect the privacy and anonymity of individuals and organisations by preventing the unintentional disclosure of information.
During collaborative document reviews, you may need to redact comments, annotations, or tracked changes before finalizing and distributing the final version of the document. Similarly, when you convert a file to PDF from Word, Excel, or other file formats,
- Compliance.
In some cases, organisations may have policies or regulations that require the removal of metadata or the redaction of personally identifiable content from documents before sharing them externally. This can be a compliance measure to prevent unintentional disclosure of sensitive information.
- Privacy and confidentiality.
PDF redaction and removal of document properties are often used to remove sensitive or confidential information such as personal details, financial information, or commercially sensitive or classified content that should not be accessed by unauthorized people.
- Streamlining processes.
In certain workflows, removing metadata can be part of a streamlining process to standardize documents or prepare them for a specific use case, such as archiving, publishing, or distribution.
- File size reduction.
PDF metadata, especially in large documents, can contribute to the overall file size. Stripping metadata may help reduce the file size, making your PDF file more suitable for sharing or uploading to online platforms with size restrictions.
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.
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Make a copy of your PDF.
Create a copy of your PDF so you can revert to your original document if you need to. -
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.
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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.
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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.
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.
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Make a copy of your PDF.
Create a copy of your PDF so you can revert to your original document if you need to. -
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. -
Choose whether to Selectively remove or Remove all hidden data.
Decide whether you want to selectively remove or Remove all hidden 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 —
- Delete PDF pages.
You can delete PDF pages online as well as in an Adobe Acrobat application. Organize pages by deleting, inserting, splitting, and more.
- Password protection.
There are two ways to use PDF password protection. One is to set a password that viewers need to open your PDF document. The other is to set a password to restrict other’s ability to edit and change the contents of your PDF. It’s easy to set passwords in an Adobe Acrobat application or password-protect a PDF online.
Related content.
Keep exploring! A few related articles on how to optimize PDFs and keep your information safe include —