How to redact in macOS Preview Preview warns if you try to draw over text, since that doesn’t actually remove it from a PDF (top). Instead, use the Redact tool, which also explains itself.

What kinds of information to redact Before we explain how to black out text in PDF, we need to understand what types of content we should redact.

When you share a PDF document, you might not want all the information it contains to be visible. Here's how to simply redact parts of a PDF.

To see alt text in a completed PDF document, you'll need to use a screen reading app, which is an accessibility tool for visually impaired users.