How to remove text from a PDF permanently

Remove the text and prove it is gone

1. Mark the text. Open the PDF in LocalRedactor, use Find to search for the words, and mark the matches, or draw boxes by hand.
2. Export. The app deletes the marked characters from the page’s instructions and paints a solid box where they were. Text near a box is left alone.
3. Let the second check run. A separate program re-reads the saved file. It looks for the removed text in the page content and in the raw bytes. If it finds any, the file is not saved.
4. Test the result. Open the saved PDF anywhere. Search for a word you removed. Select the area under a box and paste it into a text editor. Both should come up empty.

Covered is not removed

Adding a black rectangle, a highlight, or a note on top of text changes what is drawn, not what is stored. The words are still in the file, so a search, a copy and paste, or a text extraction tool brings them back. Most public redaction failures come from this.

LocalRedactor changes the stored text. The marked characters are taken out of the text instructions, the space they occupied is kept so the rest of the page does not move, and then the box is painted. Images under a box have their pixels overwritten. Notes and form fields under a box are removed.

Other places the same words can hide

• The document’s title, author and keywords. These are removed from every file you export.
• Embedded files and scripts. These are removed too, and the receipt counts them.
• Earlier versions of the page kept inside the file by an incremental save. The app writes a fresh file, and the verifier searches the raw bytes for the removed text.

What it does not do

• The text must be in the file as text, or under a box you draw. There is no OCR, so words inside a scanned image are not found by search.
• Only what you mark is removed. If a name appears eleven times and you mark ten, one is left. Search for it again on the exported file.
• Some pages use content the app does not edit directly. It asks before saving such a page as a picture, and that page’s text then cannot be selected.
• Encrypted PDFs are refused. Files over 50 MB are not opened.

Questions

Can deleted text be recovered from the exported file?

The text is removed from the page content and the file is rewritten, and the saved file is searched for the removed text before it is offered to you. Test it yourself with search and copy.

Does removing text change the layout?

No. The width of the removed characters is kept as blank space, so the rest of the line stays where it was.

What about text in images?

An image under a box has its pixels overwritten where the box sits. The app cannot read the words in an image, so you place that box yourself.