PDFViewerHow to redact a PDF (and what whiteout really does)
To redact a PDF visually in the viewer, click Whiteout, draw a box over the sensitive text and download; the box is opaque, but the original text still exists underneath it. Real redaction that deletes the text needs a tool such as Acrobat Pro's Redact, or flattening the page to an image. This page shows both so you do not send something you meant to hide.
Cover text with Whiteout in four steps
- Open the PDF here or on the whiteout tool page: drop the file or click Open a PDF.
- Click Whiteout in the toolbar.
- Drag a box over the words, numbers or photo you want hidden. The box is opaque. Draw as many boxes as you need, on as many pages as you need; the thumbnails on the left show which pages you have covered.
- Click Download. The new PDF has the boxes baked into it. The Eraser removes a box you placed wrongly before you download.
This is enough when you are hiding something from a reader who will only look at the page: a printed handout, a screenshot, a slide. It is not enough when the file itself will be handed over.
Whiteout is not redaction: what stays in the file
A PDF stores text as text, with coordinates, and draws it when the page renders. The whiteout box is a filled rectangle drawn on top. Anyone who opens your downloaded file can still press Ctrl+F and find the hidden words, select across the box and paste the text into a note, or open the PDF in an editor and move the box aside. On a scanned PDF the box covers the pixels on screen, but the full image is still inside the file.
That is the difference between covering and redacting. Redaction removes the text, image data and often the metadata, then draws the black box. Court filings, FOIA responses, medical records and HR documents leak regularly because someone covered instead of redacting. The viewer says so plainly rather than selling a whiteout as a redaction tool.
How to redact a PDF for real
| Method | Removes the text? | Where it runs |
|---|---|---|
| Adobe Acrobat Pro, Redact tool (Mark, Apply, then Sanitize Document) | Yes, including metadata with Sanitize | Windows, Mac; paid |
| Preview on macOS, Tools, Redact (macOS 11 and later) | Yes, text and image data under the box | Mac, built in |
| PDF-XChange Editor, Redact | Yes | Windows |
| LibreOffice Draw, Tools, Redact | Yes, by exporting the page as an image | Windows, Mac, Linux; free |
| Flatten to an image yourself | Yes, because the page becomes a picture | Any system |
The flatten route works with this viewer: cover the text with Whiteout, download, convert the pages to JPG or PNG (see PDF to JPG), then rebuild a PDF from the images (JPG to PDF). On a command line, Ghostscript does the same in one step: gs -sDEVICE=pdfimage24 -r200 -o redacted.pdf covered.pdf. The result is a picture-only PDF: nothing under the boxes survives, but the file is larger and no longer searchable unless you run OCR again.
When whiteout alone is enough
Covering is the right tool more often than it sounds. Hiding a phone number on a slide you will present, blanking a price on a quote you are printing for a meeting, masking a name on a screenshot you paste into chat: in all of these the audience sees pixels, not the file, and a whiteout box is quicker than a redaction workflow. The box also works on scans, drawings and photos inside a PDF, where text-based redaction tools have nothing to grab.
The test is simple: will the PDF file itself be handed to someone who must not see what is underneath? If yes, redact or flatten. If the file stays with you and only the rendered page travels (printed, projected, screenshotted), whiteout is fine. For a middle case, such as emailing a scan with one account number hidden, flatten anyway; it costs a minute and removes the doubt.
Whatever route you choose, do the covering on a copy. Download writes a new file, so the original with the full text is still on your disk; store it somewhere appropriate rather than in the same folder as the cleaned version.
Check the result before you send it
- Search for a hidden word. Open the final file and press Ctrl+F. If it finds the word, the text is still there.
- Select all and paste. Ctrl+A, Ctrl+C in a reader, then paste into a text editor. Hidden text shows up here.
- Look at document properties. Title, author and subject can carry names you intended to remove. The viewer shows them under Document properties.
- Check bookmarks and attachments. Redaction tools with a sanitize step handle these; a flattened image does too, since only page images survive.
If the goal is to change what the text says rather than to hide it, that is a different task; see how to edit text in a PDF.
Frequently asked questions
Can I redact a PDF for free?
For real redaction, Preview on a Mac (Tools, Redact) and LibreOffice Draw are free. The viewer's Whiteout is free too, but it only covers text; combine it with flattening to an image if the file will be shared.
Does whiteout actually remove text from a PDF?
No. A whiteout box is drawn over the text; the text remains in the file and can be found with search or copy-paste. Only a redaction tool or flattening to an image removes it.
How do I redact a PDF without Adobe Acrobat?
Use Preview's Redact on a Mac, PDF-XChange Editor on Windows, LibreOffice Draw on any system, or whiteout the text in the viewer and then convert the pages to images and back to PDF.
How can I check if a redaction worked?
Open the final PDF, search for a word you removed, and try selecting and copying across the black box. If nothing is found and nothing pastes, the text is gone.
Can I redact a scanned PDF?
Covering a scan with Whiteout hides it on screen, but the original scan image is still inside the file. Flatten the covered page to a new image, or use Acrobat Pro or Preview's Redact, which replace the image data.
Does blacking out text in a PDF remove it?
Not unless a redaction tool did it. A black box from a highlighter, drawing or whiteout tool is a layer on top; the words underneath stay searchable.