The word 'redact' hides two very different operations
In everyday use, 'redacting' a document means making sensitive information unreadable. Technically, there are two ways to achieve that, and they are not interchangeable. Visual redaction draws an opaque shape over content so it can't be seen when the page is displayed or printed — but the original content stream, the actual text and image data underneath, is untouched. True redaction goes further: it removes the underlying content from the file's data entirely, so there's nothing left to recover even with direct access to the file's internals.
This tool does the first kind, and says so plainly rather than letting the word 'redact' imply the second. A solid black rectangle placed over a paragraph makes that paragraph invisible in any normal PDF viewer — but the text is still there in the file, exactly as before, sitting underneath the rectangle in the content stream.
Visual redaction vs. true redaction
| Property | Visual redaction (this tool) | True redaction |
|---|---|---|
| Content hidden from normal viewing | Yes | Yes |
| Content removed from the file's data | No | Yes |
| Recoverable via copy-paste or text extraction | Yes | No |
| Recoverable by removing/moving the rectangle | Yes | No |
| Suitable for legally binding redaction | No | Yes |
| Suitable for screenshots, print previews, presentations | Yes | Yes |
Why this exists despite the limitation
Genuinely removing content from a PDF's content stream — deleting the actual text-drawing instructions rather than covering them — is a meaningfully harder engineering problem than drawing a rectangle. It requires parsing and rewriting the page's internal drawing commands correctly for every possible way content could be structured, which is exactly the kind of operation that's fragile and error-prone to implement reliably in a browser. Rather than ship a version of that which might silently fail or leave partial content behind, this tool sticks to what it can do reliably and is upfront that it's visual-only. That's still genuinely useful: for a screenshot you're about to share, a print preview, or a presentation slide, hiding sensitive content from view is exactly what's needed — the underlying file's data isn't the thing anyone's looking at.
Redacting a PDF
Drop a PDF onto the zone.
Click Add to create a redaction rectangle.
Set the page (1-indexed), X/Y position, width, and height, all in PDF points.
Click Redact & download to save the result.
Positioning your rectangle correctly
Like other tools in this suite built on pdf-lib, positions are specified in PDF points with the origin at the bottom-left corner of the page, Y increasing upward — the opposite of typical screen coordinates. Width and height define the rectangle's size starting from the X/Y position you set, extending rightward and upward. To fully cover a line of text, size the rectangle generously beyond the visible text boundaries in both directions — a rectangle sized to the exact visible width of text at one zoom level can leave slivers exposed at another, since text rendering can shift subtly across viewers and zoom levels.
How content can still be recovered from a visually redacted PDF
It's worth being concrete about why this matters rather than just asserting it: selecting text in a PDF viewer works by reading the underlying text objects in the content stream, not by reading pixels. A black rectangle drawn on top of text changes what's visually painted last, but it doesn't change what text objects exist underneath — so a simple click-and-drag text selection, or an automated text-extraction script, can pull the 'hidden' text out without any special tools. This is the exact mechanism by which supposedly redacted government and legal documents have leaked sensitive information in the past: someone assumed a black box meant deletion, when it only meant visual overlay.
Common mistakes
Using this for anything with legal or compliance requirements — court filings, medical records, anything subject to discovery — where recoverable content is a real liability.
Sizing the rectangle too tightly around the visible text, leaving edges exposed if the recipient views the PDF at a different zoom or in different software.
Forgetting that recipients can simply select and copy the 'hidden' text, or extract it programmatically, without needing to remove the rectangle at all.
Assuming this tool's honesty about its limitation means it's not useful — for the right use case (screenshots, print handouts, internal review copies), it's exactly the right tool.
Real use cases
Blacking out a signature or account number before taking a screenshot of a document for a support ticket.
Hiding sensitive figures on a printed handout for an internal meeting where the underlying digital file never leaves your control.
Covering a section of a document before presenting it on-screen, where only the visual display matters.
Preparing a quick visual mockup of what a fully redacted document will look like before doing true redaction with dedicated software.
Frequently asked questions
Q: Is the underlying text really removed?
A: No — it's only hidden behind a black rectangle. The text can still be copy-pasted or extracted. For true removal, which deletes the content stream, use Adobe Acrobat's redaction feature or qpdf.
Q: Why ship a tool that doesn't truly redact?
A: Because true redaction requires modifying the PDF content stream, which is error-prone to do reliably in a browser. The visual hiding is still genuinely useful for screenshots and print previews, and the limitation is stated upfront rather than implied away.
Q: Can recipients remove my rectangles?
A: Yes, with the right tools. Never rely on this for legally binding redaction.
Q: Is my PDF uploaded?
A: No. Drawing happens entirely in your browser via pdf-lib.
Q: If I need real, unrecoverable redaction, what should I actually use?
A: A dedicated redaction feature that strips the content stream, like Adobe Acrobat's built-in redaction tool or qpdf — both are designed specifically to remove the underlying data, not just cover it.
Q: Could I combine this with cropping to make content harder to recover?
A: Cropping and redaction solve different problems — Crop PDF hides content outside a visible boundary the same non-destructive way this tool hides content under a rectangle, so combining them doesn't add real removal; the underlying data remains in both cases.
Redact your PDF now
Cover sensitive content with the Redact PDF tool. Need to add other annotations instead? Try Edit PDF. Want a repeated overlay like a confidentiality marking? Use Add PDF Watermark, or add a real access barrier around the whole file with Protect PDF.
