How to Black Out Text in a PDF
When a PDF contains information you should not share, a black rectangle is not always enough: it may cover the words on screen without removing them from the document. Use redaction when the content must be concealed, then check the saved copy before sending it. The right approach depends on whether you need to remove information throughout the file, handle a scan, or work on only a few pages.
Remove sensitive text rather than just hiding its appearance
First decide whether the information must be unavailable to the next person, or whether you only want a temporary visual mark for your own review. Drawing a dark shape over words can change what a page looks like while leaving the original text underneath. Someone may still be able to select, copy, search for, or expose that text, so a visual cover is not a safe substitute for redaction.
For names, account details, addresses, or other private content, make a separate working copy of the PDF and identify every place the information appears. Redact the content itself rather than placing a shape over it. The redact-pdf tool is intended for removing sensitive PDF content; it processes the whole file, so review the complete document for other occurrences before using it. Keep the untouched original somewhere safe in case you need to compare or redo the work.
After you save the redacted copy, open that copy and inspect each affected page. Try selecting or searching for the removed words, and check that the visible result is what you intended. If the information is especially sensitive, also check the document’s metadata and avoid sharing the original by mistake. A careful review is worthwhile because a missed duplicate, header, or footer can undermine an otherwise correct edit.
When you need to cover only a few pages
If the sensitive material appears on just a small part of a long PDF, decide whether you want to create a separate file containing only those pages. The redact-pdf tool processes the whole file and does not select a page range. Do not assume you can choose a single page within that tool; prepare the smaller document first if processing every page is not what you need.
Use extract-pages to make a PDF from the pages you need, then work on that extracted copy. Before redacting, confirm that it includes every page with relevant information, including any continuation page or attachment. Apply redaction to the extracted file and check the result before sharing. Keep in mind that this creates a focused copy; it does not remove the same content from the original full document.
If you need to share both the full document and a version with some information concealed, treat them as two separate deliverables. Give the redacted version a clear filename, and open it once more before attaching it. This simple separation helps prevent accidentally sending the unredacted original when you meant to send the edited copy.
If the page is a scan or the words cannot be selected
A scanned page may be a picture of text rather than editable text. Try selecting a word on the page: if nothing is selected, or the selection does not follow the printed words, you may be looking at an image-based scan. Zoom in to locate the exact area that contains the private information, and check nearby lines, labels, and handwritten notes as well.
Do not rely on being unable to select the words as proof that they are safe. The image itself can still reveal the information. Use a redaction workflow that covers the sensitive area in the resulting PDF, then inspect the saved page at normal size and zoomed in. Pay particular attention to small characters near the edges of the marked area, where part of a name or number can be easy to miss.
If the PDF mixes ordinary text with scanned pages, check both kinds of page. Searchable text may be present on some pages while other pages are only images. Review the entire copy after editing, rather than assuming one successful text search proves every page has been handled.
Check repeated details and document information before sharing
Sensitive information often appears more than once. Search the document for the same name, number, or phrase, and review page headers, footers, tables, image captions, and appendices. A detail may also appear in a different format, such as a shortened account number or an email address printed inside a screenshot. Make a brief checklist of the items and locations you need to conceal, then use it during the final review.
The redact-pdf tool can help remove sensitive content, and its available options include removing metadata. Metadata is information about the document rather than text displayed on the page, so checking it is a separate part of preparing a shareable copy. If you use the tool for this purpose, review the saved document and its visible pages as well; metadata cleanup does not replace checking the page content.
Before sending the file, close it and reopen the saved copy. Confirm that the blacked-out areas stay concealed, that unrelated text remains readable, and that the filename identifies the correct version. If you are sharing through an upload form, select the reviewed copy rather than an earlier download or the untouched original.
Choose a method that matches how the PDF will be used
For information that must not be recoverable from the shared document, use redaction and verify the output. For a draft where you only need to point out text for discussion, an annotation can be more appropriate because it marks up the document rather than serving as a promise that the underlying words have been removed. Decide which purpose applies before editing, especially when a file will leave your device or be used as an official record.
If you are only preparing a copy for review, keep a clean original and make edits to a duplicate. This gives you a way to recover the source if you mark the wrong line or conceal too much. If the document contains information governed by workplace or legal rules, follow the process required for that material rather than relying on a visual check alone.
The redact-pdf tool is the relevant option when the goal is to conceal content in a PDF; it works on the whole file. If only selected pages belong in the working copy, extract those pages first. In either case, the practical final step is the same: open the file you intend to share and verify the concealed areas and the surrounding content.
Frequently asked questions
Is drawing a black box over PDF text enough?
Not necessarily. A shape may hide words visually while leaving the original text in the file. For sensitive information, use redaction and inspect the saved copy before sharing it.
Can I redact only one page with the redact-pdf tool?
The redact-pdf tool processes the whole file rather than selecting individual pages. If you need a smaller working document, use extract-pages to create it first, then redact that copy.
What should I do if I cannot select text in a scanned PDF?
Treat the page as an image that may still reveal the information. Locate the sensitive area visually, redact it, and review the saved page closely, including nearby small print.
How can I check that the edited file is ready to share?
Reopen the saved copy, inspect every affected page, and search or select the words where possible. Also confirm that you are sharing the redacted version, not the original.