Redact a PDF on a Mac

On a Mac the first place to look is Preview, which comes with every Mac and, in recent versions of macOS, has a real redaction tool. For a short document with a few typed lines to remove it is enough. The trouble starts with long documents, logos and scans.

Open the tool Free below twenty pages, in your browser. Nothing is uploaded.

A market slide with both company logos in the header and again in the footer, over a Venn diagram of countries and sales figures. — A slide before and after: the two company logos in the header and the two in the footer are each replaced with a labelled black bar.

A slide before and after: the two company logos in the header and the two in the footer are each replaced with a labelled black bar.

Redacting in Preview

In recent versions of macOS, Preview has a Redact tool under the Tools menu. Select text, or drag across an area of the page, and it is marked; when the file is saved, the marked content is removed rather than hidden. That is proper redaction, and it costs nothing.

Do not confuse it with Markup. A black rectangle drawn with the Markup toolbar, in Preview or Quick Look, is an annotation on top of the page. The text underneath is still there to be selected and copied.

Where Preview stops

Preview redacts what you select, one passage at a time. It can search for a word, but it does not mark every result for you, so a name that appears sixty times is sixty selections. A logo has no text to search for, so each copy of it is a box you draw by hand, page by page, and the small one in a footer is the one that gets missed. Words inside pictures and scans are the same: you have to find them by eye.

None of that is wrong. It is a manual tool, and manual redaction on a long document misses things.

Finding every copy instead

Blinded runs in Safari, Chrome, Firefox or Edge on a Mac, with nothing to install. Type a name once and every mention is found on every page: in the text, in the lettering of screenshots and scans, and inside logos. Draw a box round a logo once and every other copy is found by what it looks like, at any size or colour. Every find is listed by page before anything is covered.

The export rebuilds each page from pixels, so what was under a bar is not in the file, and no metadata comes across from the original. Turn on searchable text if the result needs to be searchable again.

Keynote and Pages files

Blinded opens PDFs and images, not Keynote or Pages files directly. Export to PDF first: in Keynote or Pages, File, Export To, PDF. That keeps every slide exactly as it looks, and the redacted PDF is also the right thing to send, because a redacted Keynote file can still hold the original pictures inside it.

Nothing is uploaded

The file never leaves your Mac. It is opened and rebuilt in the browser tab, and the page is not permitted to send anything anywhere; turn off Wi-Fi after the page has loaded and it keeps working. Documents up to 20 pages are free.

How to do it, in four steps

Open the PDF in Safari or any browser on your Mac. Nothing is installed or uploaded.
Type each name once, and draw a box round each logo once.
Check the list of what was found, page by page.
Redact and export. The pages are rebuilt, so nothing is left underneath.

Who it is for

Mac users without Acrobat Pro who have outgrown selecting one passage at a time in Preview, or who need logos, letterheads and scanned pages redacted as well as typed text.

Open the tool

Questions

Does Preview redact properly?

Its Redact tool, in recent versions of macOS, removes the selected content when you save. A black box drawn with Markup does not: it only covers the text.

Do I need to install anything?

No. Blinded runs in Safari, Chrome, Firefox or Edge, and keeps working offline once the page has loaded.

Can it redact a Keynote deck?

Export the deck to PDF first, from File, Export To, PDF. The redacted result is a PDF.

Is the file uploaded?

No. Everything runs in your browser, and the page is not permitted to send anything anywhere.

Also

Back home