Redact a PDF

Permanently remove confidential text, images and graphics from a PDF: mark what to remove with Redact, then Apply Redactions to delete it and cover the spot with a black box.

Available in pre-release 3.7

Select the text, right-click → Annotations → Create From Selection → Redact, then Annotations → Apply Redactions, then save to a new PDF. At a glance:

Mark: Redact (CmdCreateAnnotRedact) marks selected text, or an area you drag out. Marks are red outlines.
Apply: Apply Redactions (CmdApplyRedactions) removes everything under every mark and draws black boxes.
Undo: Ctrl + Z brings the content back until you save.
Save: Ctrl + S saves to a new PDF.

A mark on its own removes nothing: the text is still in the file until you apply the redactions and save.

Mark text for redaction #

Select the text.
Mark it in any of these ways:
- Right-click → Annotations → Create From Selection → Redact
- Redact button on the Edit PDF toolbar
- Ctrl + K, then Create Redact Annotation in Command Palette

The selected text gets a red outline. Repeat for everything you want to remove.

Mark an area for redaction #

Use this for images, signatures, or anything that isn’t text.

With no text selected, click the Redact button on the Edit PDF toolbar (or Ctrl + K, Create Redact Annotation).
Mark content for redaction. Drag or click twice. Drag a rectangle over the area, or click two opposite corners. Esc cancels.

Change or remove a mark #

Marks are annotations. In Edit PDF mode, click a mark to select it, drag it to move it, or press Delete to delete it.

Apply the redactions #

Apply every mark in the document in any of these ways:

Right-click → Annotations → Apply Redactions
Apply Redactions button on the Edit PDF toolbar, next to Redact. It shows up once you’ve marked something.
Ctrl + K, then Apply Redactions in Command Palette

The command is available only while the document has redaction marks. It also applies marks that came with the PDF.

What applying does, under each mark:

Text is deleted from the page. It can no longer be selected, searched or copied.
Images: the covered pixels are blanked; the rest of the image stays.
Vector graphics (lines, shapes, table borders) that touch the mark are removed, even the parts outside it.
A black box is drawn over the area.

The marks disappear and Redactions applied. is shown. Ctrl + Z (Undo) restores the content until you save.

Save the redacted PDF #

Save to a new file so you keep the original:

Ctrl + S, or Ctrl + K, then Save Annotations to a new PDF (CmdSaveAnnotationsNewFile)
Right-click → Annotations → Save to new file, or the tab’s context menu → Save changes to new PDF

Ctrl + Shift + S (Save changes) overwrites the original.

After redacting, SumatraPDF writes the whole file anew rather than appending the change, so the removed content is not left in an older revision inside the file. Once saved, the redaction can’t be undone.

Check the result #

Open the saved PDF and make sure the content is gone:

Search for the redacted text with Ctrl + F.
Try to select text where the black boxes are.
From the command line, search the file: sumatrapdf-tool grep "123-45-6789" redacted.pdf prints nothing when the text is gone. See sumatrapdf-tool grep.

Note: only content under the marks is removed. The same text elsewhere — on other pages, in bookmarks, in document properties, in attachments — stays.

Tips #

Mark everything first, then apply once.
Use an area mark over images and scanned pages: scanned text is a picture, and text search won’t find it.
Leave a margin around graphics you don’t want removed; any line that touches a mark goes.
Search the whole document (Ctrl + F) for every occurrence before you apply.