How to Redact a PDF (Permanently Remove Text, Not Just Cover It)

If you searched "how to redact a PDF," you probably need to permanently remove sensitive information before sharing a document. Maybe you are filing a legal document that requires social security numbers to be blacked out. Maybe you are sharing a contract with a third party and need to remove financial details. Maybe you are responding to a FOIA request or preparing a document for public release.

Redaction sounds simple: draw a black box over the sensitive text. But most people get it wrong, and the consequences can be serious. A black rectangle drawn in a PDF editor is just a visual overlay. The original text is still in the file, and anyone can copy it, select it, or extract it with basic tools. True redaction means the text data is permanently destroyed. This guide covers how to do it correctly.

Why drawing a black box in a PDF editor is not redaction

This is the most common and most dangerous mistake people make with PDF redaction:

• The text is still in the file. When you draw a black rectangle over text in a standard PDF editor (like Preview on Mac, or a free PDF annotator), you are adding a shape on top of the text. The text layer underneath remains intact.
• Anyone can copy and paste it. Select all text in the PDF, paste it into a text editor, and every "redacted" word appears in plain text. This is how high-profile redaction failures happen.
• Screen readers ignore visual overlays. Assistive technologies read the underlying text layer, not the visual shapes. A "redacted" document read by a screen reader exposes everything.
• PDF text extraction tools see through it. Any tool that extracts text from a PDF (and there are many) will pull the original text, completely ignoring black boxes drawn on top.
• Highlighting and changing color to black is also not redaction. Some people highlight text and change the highlight color to black. This is equally ineffective because the text data remains unchanged.

The only way to truly redact a PDF is to remove the text data itself from the file, not just cover it visually.

How to redact a PDF step by step

Open the PDF Redactor, upload your PDF, draw redaction boxes on any page, and download the redacted file with the text permanently removed.

Step by step

1. Upload your PDF to the PDF Redactor. Drag and drop or click to select the file.
2. Navigate to the page containing sensitive content. Use the page controls to move between pages.
3. Draw redaction boxes. Click and drag to draw a black box over any text you want to remove. You can draw multiple boxes on any page.
4. Review your redactions. Scroll through the document to verify that all sensitive content is covered. The toolbar shows how many redactions you have placed on each page.
5. Download the redacted PDF. Click Download. The tool renders each page as an image, applies the redaction boxes, and recomposes the PDF. The original text layer is destroyed in the process.

What makes this real redaction

The key difference between this tool and drawing shapes in a PDF editor is how the output file is constructed:

How it works: Each page of the PDF is rendered to a high-resolution image. The redaction boxes are burned into the image, covering the text visually. The page is then recomposed as a new PDF page from this flattened image. The original text layer, including all characters, fonts, and metadata underneath the redaction boxes, is not carried over to the new file.

What this means: The redacted text does not exist in the output file in any form. It cannot be selected, copied, searched, or extracted. It is gone. The output PDF contains only the visual image of the page with the redaction boxes permanently applied.

This is the same approach used by professional redaction tools like Adobe Acrobat Pro's built-in redaction feature. The difference is that this tool does it for free, in your browser, without installing any software.

When to redact PDFs

Legal filings. Courts often require sensitive information like social security numbers, financial account numbers, or minor's names to be redacted before filing. Proper redaction ensures this data is truly removed, not just visually hidden.

FOIA and public records requests. Government agencies responding to Freedom of Information Act requests must redact exempt information (personal data, trade secrets, security details) before releasing documents to the public.

Sharing contracts with third parties. When sharing a contract with someone who should not see certain financial terms, party names, or proprietary details, redact those sections before sending.

GDPR compliance. When sharing documents that contain personal data (names, addresses, email addresses), redact the personal information to comply with data protection regulations before distributing to unauthorized parties.

Internal review. Preparing sensitive documents for wider internal distribution, such as board meeting minutes or investigation reports, where certain details should be restricted to specific audiences.

How does this compare to other methods?

Your files never leave your device

All processing happens locally in your browser. Your PDF is not uploaded, stored, or transmitted anywhere. The rendering, redaction, and recomposition all happen on your device. This is especially important for redaction, where the whole point is to protect sensitive information. Uploading a document full of sensitive data to a server in order to redact it defeats the purpose entirely.

Frequently asked questions

Is the redaction truly permanent?

Yes. The tool renders each page as an image with the redaction boxes burned in, then recomposes the PDF. The original text layer is destroyed. The redacted text cannot be recovered, selected, copied, or extracted from the output file.

Does it work with scanned PDFs?

Yes. Since the tool renders each page as an image regardless of the PDF's internal structure, it works with both text-based PDFs and scanned/image-based PDFs.

Can I redact multiple pages?

Yes. Navigate between pages using the page controls and draw redaction boxes on any page. The tool handles the entire document.

Can I undo a redaction before downloading?

Yes. While you are placing redaction boxes (before downloading), you can remove or adjust them. Once you download the redacted file, the redaction is permanent and cannot be undone.

Will the file size change?

The output file may be larger or smaller than the original, depending on the content. Since each page is rendered as an image, text-heavy PDFs may increase in size, while image-heavy PDFs may stay similar.

Is the text really gone, or just hidden?

It is gone. Unlike drawing a black box in a PDF editor (which leaves the text in the file), this tool destroys the text layer entirely. If you open the output file and try to select text under the redaction boxes, there is nothing there.

Does it work on a Mac?

Yes. The tool runs entirely in your browser, so it works on Mac, Windows, Linux, Chromebook, or any device with a modern browser. Preview on Mac can draw black shapes over text, but that is a visual overlay, not true redaction.

Is it safe to use with confidential documents?

Your files never leave your device. Nothing is uploaded, stored, or visible to anyone. Processing happens entirely in your browser, and all data is gone when you close the tab.