Before you share a contract, a court filing, a bank statement or an HR document, some of it may need to disappear: account numbers, home addresses, salaries, the names of people who aren't party to the matter. Redaction means removing that information so nobody who receives the file can get it back. The S-PDF redact PDF tool lets you mark what should go, either by drawing boxes or by searching for words, and then removes it for good.
The important part is what happens when you click Redact PDF. Every page that contains a redaction is rebuilt as an image with the black boxes burned in, so the original text and graphics underneath no longer exist in the file. Pages you didn't touch stay exactly as they were.
How to redact a PDF
- Upload your PDF Drag the PDF onto the upload box or select it from your device. Page previews appear so you can see what you are marking.
- Draw boxes over what must go Drag a box across any text, signature, photo or table on a page preview. Draw as many boxes as you need, on as many pages as you need.
- Search for words and phrases Type a name, an account number or a phrase and every match on every page is marked at once. Remove any individual mark you don't want.
- Redact and download Leave Remove document metadata ticked, click Redact PDF, then download the redacted copy and check it before you share it.
Why use S-PDF for Redact PDF
- True redactionMarked content is permanently deleted from the file, so copy and paste or moving a box can never reveal it.
- Find every occurrenceSearch marks each match of a word or phrase across all pages in one go, so a repeated name is not missed.
- Draw by handBoxes drawn on the page previews cover anything search cannot find, such as signatures, photos and stamps.
- Untouched pages stay intactPages without redactions are left unchanged, with their text still selectable and searchable.
- Metadata removedAuthor, title, subject and XMP metadata are stripped by default, so hidden details don't travel with the file.
- Private processingFiles are kept in private storage and deleted automatically one hour after your last action.
Why a black highlighter is not redaction
Most PDF editors let you draw a black rectangle or highlight text in black. On screen, the result looks redacted. In the file, the text is still there, sitting underneath a shape. Anyone who receives it can select the hidden text and paste it into an email, search for it, move or delete the rectangle, or run the file through a text extractor. Sensitive details have been exposed this way in published legal and government documents more than once.
Real redaction removes the content itself. S-PDF does that by re-creating each redacted page as a 200 dpi image with the boxes burned in. There is no text layer under the black area any more, nothing to copy and no shape to move aside. The trade-off: text on redacted pages can no longer be selected or searched. If you need that back, run the result through OCR PDF; it will recognise the visible text and can't recover what is under the boxes.
Common redaction mistakes to avoid
- Missing a repeat. A name redacted on page 2 still appears in a footer on page 14. Use search to mark every occurrence, then scroll through all the pages.
- Forgetting variants. Search for each form separately: "Jane Doe", "J. Doe", "Ms Doe", the account number with and without spaces.
- Leaving metadata behind. The document title or author field can reveal exactly what you redacted. Keep Remove document metadata ticked.
- Trusting search on scans. Search finds only text that the PDF actually contains. On a scanned page without a text layer, draw the boxes by hand.
- Boxes that are too tight. Cover the whole word with a little margin, including the tops and tails of letters, so its length and shape don't give it away.
- Sharing the wrong file. Name the output clearly and open it before sending. Try selecting text under a box to confirm nothing is there.
Before and after: preparing a document for sharing
If only part of a long document needs to go out, first use Extract pages to keep just those pages, then redact them. Pages turned into images usually take more space than text pages, so if the redacted file is too large to send, run it through Compress PDF afterwards. Always keep your unredacted original somewhere safe: redaction cannot be undone, which is the point.
Frequently asked questions
Is the redacted text really gone?
Yes. Each page with a redaction is rebuilt as an image with the black boxes burned in, so the hidden text and graphics no longer exist in the file. Copying, searching or removing a box cannot bring them back.
Why can I no longer select text on some pages?
Pages that contain a redaction are converted to images, which is what makes the redaction permanent. Pages without redactions keep their selectable text. Run OCR PDF afterwards if you need the redacted pages to be searchable.
Can I redact every occurrence of a word at once?
Yes. Search for the word or phrase and every match across all pages is marked in one step. You can then remove individual marks before redacting.
Does it remove metadata too?
By default, yes. The Remove document metadata option strips the author, title, subject and XMP metadata. You can untick it if you want to keep them.
Can I redact a scanned PDF?
Yes, by drawing boxes on the page previews. Search only works where the PDF contains real text, so on scans without a text layer, mark the areas by hand.
Is it free to redact PDF files?
Yes. Free use covers 5 tasks a day with files up to 50 MB per task, with no signup and no watermark. Pro ($5 a month or $50 a year) raises the limit to 500 MB per task with unlimited tasks under fair use and no ads.
Can I undo a redaction?
Not in the redacted file; that is what makes it safe to share. Keep the original, and redact it again if you need a different version.
Are my documents safe while I redact them?
Files travel over HTTPS, are stored privately, never shared or reused, and are deleted automatically one hour after your last action. The Delete my files now button removes them immediately.
Last updated by The S-PDF team.