How to Redact a PDF Permanently (Remove Sensitive Text for Good)
Before you share a contract, a statement or a report, you often need to take out a name, an ID number, an address or a figure. Many people draw a black rectangle over it and send the file. That looks safe, but it is not: the text is usually still there under the box, and anyone can select it, copy it or find it with search.
Real redaction removes the words from the file. Here is how to do it.
Covering is not the same as removing
| Method | What happens to the words | Safe for sensitive data? |
|---|---|---|
| Black box or white-out drawn on top | Still in the file, only hidden | No |
| Highlight in black | Still in the file, only coloured | No |
| Redaction | Removed from the file | Yes |
If you ever see a "redacted" PDF where you can select the black bars and paste the words, that is what a cover-up looks like.
How to redact a PDF
- Open the Redact PDF tool and add your file.
- Choose how to mark what must go. You can use either way, or both:
- Draw areas: drag a box over the part of the page you want removed.
- Type words to find: enter names, numbers or phrases (up to 50), and every occurrence is covered. You can ask it to match upper and lower case exactly.
- Choose the output quality (100, 150, 200 or 300 dpi). Higher is sharper and gives a larger file.
- Press the Redact PDF button and download the result.
Why the result cannot be selected or searched
To remove the words for real, each page is rebuilt as a picture and the finished file is checked to confirm that the redacted text cannot be extracted. The price of this is that none of the text in the result can be selected or searched any more, not only the redacted parts.
If you need the remaining text to be searchable again, run the file through OCR PDF afterwards. The words you removed stay removed, because they no longer exist anywhere in the file.
Choosing the quality
| Output quality | Good for |
|---|---|
| 100 dpi | Small files for screen reading |
| 150 dpi | A good default for most documents |
| 200 to 300 dpi | Small print, tables, or pages you plan to print |
Tips
- Keep the original. Redaction cannot be undone, so work on a copy and store the untouched original safely.
- Use word search for names and numbers. It finds every occurrence, including ones you would miss by eye.
- Check every page of the result before you send it, especially tables and footers.
- Think about the whole page, not only the words. A name can also appear in a header, a footer or a signature line.
- If a whole page should go, it is simpler to remove the page (see our guide).
- After redacting, you can add a password with Protect PDF (see our password guide).
What redaction does not do
Redaction removes the words you mark. It does not decide for you what is sensitive, and it does not fix identifying details you did not mark. Review the document yourself before sharing it.
Is my file safe?
Your file is encrypted in transit and at rest and deleted automatically, by default within 2 hours. Words you type to search for are removed from our records when the job finishes, because they are the very text you are erasing. See the privacy page.
Frequently asked questions
Why is covering text with a black box not enough?
A box drawn over text only hides it visually. The words are still inside the file, and anyone can select, copy or search them. Redaction removes them from the file itself.
Can I redact words automatically?
Yes. Type the words you want gone (up to 50), and every occurrence is found and removed. You can also draw areas on the page by hand.
Why can I not select text in the redacted file?
To remove the words for real, every page is rebuilt as an image. This is what makes the redaction permanent, and it means none of the remaining text is selectable either.
Can I make the result searchable again?
Yes. Run the redacted file through OCR PDF. The removed words stay gone, because they no longer exist in the image.