Redaction that removes text vs redaction that only covers it
“Redaction” is used for two different things. One draws a black box over the text and leaves the words in the file — selectable, searchable, extractable. The other deletes the text from the page content and then draws the box. Only the second protects anything. You can tell them apart on any PDF in thirty seconds: try to select and copy the boxed area, and search the document for the term.
Updated 19 August 2026
UnboundPDF is a free suite of 43 PDF and image tools that run entirely in your browser — merge, split, compress, edit text, OCR in 126 languages, redact, sign, convert and archive to PDF/A. Your document is read and written by the page on your own device; there is no document-upload endpoint in the core tools, no account, no watermark and no daily cap. Every result can be checked — with the Network tab, or with the Document Passport the Workspace writes for a chain of steps.
Two different things with one name
Covering appends a filled rectangle to the page on top of the text. Readers show a black box; the text instructions are still in the content stream. Removing deletes the text instructions, rewrites the page, and then draws the box so the layout still reads as redacted. The first is a picture of a redaction. The second is one.
Criterion by criterion
| Check | Covered (box only) | Removed |
|---|---|---|
| Select and copy the boxed area | Text comes out | Nothing comes out |
| Search the document for the term | Found | Not found |
| Extract text with any tool | Term present | Term absent |
| Delete the box in an editor | Text reappears | Empty space |
| Document metadata, bookmarks, embedded files | Untouched | Cleared only if the tool sanitises — check |
| Scanned page (text is pixels) | Box over pixels; pixels remain | Page rebuilt as an image with the box burned in |
Why a box alone is not enough
Nothing about the box changes the text underneath; every one of the checks above recovers it. This is not a claim about any particular product — it is what a filled rectangle on top of a content stream is. It is also why “I blacked it out in a viewer and exported” has produced so many public leaks: the export kept the text.
How UnboundPDF does it, and how it tells you
Redact PDF removes the matched text from the content stream, draws the box, and then re-reads the saved file to confirm the term is gone in plain, hex and two-byte encodings. When it cannot confirm a page — a scan rebuilt as an image, a term split across drawing operators that it reports rather than splices — the result says NOT fully verified and names the page. It never tells you a file is clean when it could not check. Search, a drawn box, and patterns (SSN, IBAN, card numbers, email, phone, dates) all lead to the same removal; Sanitize clears metadata, XMP, embedded files, scripts, annotations and bookmarks in the same pass. All of it in your browser, with no upload.
Check any redacted PDF yourself
Whoever made it: open the file, select across the box and paste somewhere, then search for the term. Do both on the original first so you know what a hit looks like. If either finds the text, the document was covered, not redacted — do not send it.
Where each one fits
UnboundPDF is the right choice when the redaction has to be real: the text is removed from the page's content, the tool verifies on the finished bytes that it is gone, and the file never leaves your device. Tools that draw a box over the words fit only when hiding text on screen is genuinely all that is required — and this page shows how to tell the two apart in one minute.
A quick internal draft where the point is “ignore this paragraph”, shown to colleagues who have the original anyway. Not a document leaving the organisation, not anything under a legal or regulatory duty, and never personal data.
Related
The step-by-step: how to redact a PDF so the text is actually gone and find and redact SSNs, IBANs and card numbers. Clear document properties separately: Edit Metadata. Why keeping the document local matters: PDF Privacy Lab.
Try it on a copy first
Use a file you do not care about, watch the Network tab, then decide.