What is the difference between blur, pixelate, and fill?
Blur softens the area, pixelation makes the edit more explicit, and fill covers the area completely with a solid block.
Does this upload images to a server?
No. The full redaction workflow runs in the browser, so the image stays on the device while you prepare the export.
Can I apply multiple redactions before exporting?
Yes. You can stack repeated blur, pixelate, or fill actions on the same image before exporting it.
What is the difference between blur, pixelate and fill?
Fill destroys the information: the pixels in that rectangle are replaced with a flat colour and are gone from the exported file. Blur and pixelate transform the pixels in ways that are mathematically reversible under the right conditions, and text hidden with either has been recovered. Only fill is a redaction.
Why is a black box on an image safer than a black box on a PDF?
Because a PDF is a document with objects and layers, and a rectangle drawn over text sits above text that is still in the file, extractable with a copy and paste. This tool rasterises the image and paints the fill onto the pixels, then encodes a new file. There is nothing underneath to recover.
Should I ever use blur on a document?
No. If it is text, use a fill. Blur has been reversed on redacted screenshots repeatedly, and a blur radius that looks convincing to the eye can still be defeated by rendering candidate text and matching the blur output.
Does exporting strip the metadata?
Redrawing through a canvas drops the original EXIF, including GPS, so the exported file is cleaner than the source. That is a side effect rather than a stated feature, so if metadata is the main concern, use a metadata remover as an explicit step.
Does the image leave my device?
No. Decoding, redaction and encoding all happen in the browser, which is the only defensible way to run a redaction tool.