Black out names, numbers and passages so they are actually removed from the file — not merely hidden behind a rectangle. Entirely in your browser.
The famous cases all share one mechanism: someone drew a black rectangle over text in a PDF editor and shipped the file. A PDF draws in layers, so the text was still there — underneath the rectangle, fully intact, one copy-paste away. Court filings, government reports and corporate disclosures have all leaked this way.
Marking a region records it as a redaction rather than as a drawing. On export, every page carrying a mark is re-rendered into a bitmap, the marked rectangles are filled opaque black in that bitmap, and the resulting image replaces the page. The original text objects never make it into the output file, so there is nothing left to extract.
Redacted pages become pictures. Text on those pages is no longer selectable or searchable and the file gets larger. That is why only marked pages are converted — the rest of your document keeps its searchable text.
Redacting the page body is necessary but not sufficient. Clear the title and author in the metadata panel, remember that filenames travel with the document, and check whether an attachment or an earlier revision is embedded. For a fully flattened document with no text layer at all, run the whole file through PDF to PNG and rebuild it with PNG to PDF.
Real. Pages with redaction marks are re-rendered as images on export, with the marked areas painted opaque black before encoding. The original text objects are not part of the rebuilt page, so copying, searching or extracting text cannot recover them.
Redacted pages become images: their remaining text stops being selectable and searchable, and file size usually grows. Only pages you actually marked are affected — the rest of the document keeps its real text.
A rectangle is drawn on top of the text, and the text is still in the file underneath. Selecting the area and copying, or running any text extractor, reveals it. This is the mistake behind most published redaction failures.
No. Rendering, redaction and saving all happen inside your browser — which matters more here than anywhere else on this site, because the whole point is that certain people must never see this content.
Set the metadata fields to blank in the editor’s Document metadata panel before exporting. Author names and titles are a common leak that redacting the page body does not address.