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Pixels destroyed, not covered · flattened export

Redact a document to PDF

Drawing a black rectangle in a PDF viewer leaves the text sitting underneath it. This flattens the image first, so what you blacked out is actually gone from the file you share.

Black out or pixelateFlattened PDF exportNo uploadPNG export too

Load a scan, drag over what must go

Everything happens on this page. The file is never uploaded.

Scan, photo or screenshot
Areas0
Next stepChoose an image to start
Download PNG

Redaction is applied to the pixels before export. Solid black is the safest option for anything genuinely sensitive.

How it works

  1. Your image is drawn on a canvas at up to 2000 px on the long edge. Every redaction is repainted onto those pixels, not stored as a separate layer.
  2. Black mode fills the rectangle with solid black. Pixelate averages each block and writes the average back, so no original values survive inside the area.
  3. Export re-encodes the finished canvas as JPEG and wraps it in a minimal one-page PDF written by this page — the PDF contains only the flattened image.
  4. Undo removes the last area and repaints from the original, so mistakes cost nothing.

What it will never do

  • It cannot open a PDF. Browsers cannot render PDF pages without an external library, and this page loads no external code. Export or screenshot the page as an image first — which is also what makes the redaction safe.
  • It does not remove metadata from your source file, because it never reads it; the export is a fresh canvas render.
  • Nothing is uploaded, and no copy is kept when you close the tab.

Questions

Why is drawing a black box in a PDF editor unsafe?

Because most editors add the rectangle as a new object on top. The original text is still in the file and can be selected, copied or extracted. Flattening to an image, as this page does, removes it for real.

Black out or pixelate — which is safer?

Solid black. Pixelation with a small block size can sometimes be attacked when the underlying content is predictable, such as a short number. For anything sensitive use black.

Can I redact several pages?

One image per pass, exported as a one-page PDF. For multi-page documents, redact each page and then combine them with the JPG-to-PDF tool listed below.

Redacting files on iPhone regularly?

Mask My File is optional — this free tool runs entirely in your browser and works without it. Check the app’s current App Store listing for exact features, pricing and availability before downloading.

View Mask My File on the App Store