Why use a white box instead of a black one?
A white box can fit bright screenshots, forms, and document backgrounds better while still hiding the selected area completely.
Can I switch this to another color?
No. This page is intentionally fixed to white-box redaction so the tool stays focused on one specific masking style.
Does this run fully in the browser?
Yes. The image stays on the device during editing and export.
Is a white box as secure as a black box?
Yes. Both replace the pixels in the rectangle with a flat colour and the export is re-encoded from that canvas. The security comes from the opacity and the flattening, not from the colour.
When should I use white rather than black?
On light backgrounds. A white box on a document scan or a light-mode UI looks like an empty field rather than a redaction bar, which is what you want when you are showing a product screenshot rather than disclosing a court document.
What is the risk of a white box?
That you cannot see it. On a white page it is easy to draw a box in the wrong place, or to think you have covered a field when you have not. Zoom in and verify every region before exporting.
Will the redaction show as a JPEG artefact?
It can. JPEG compression around a hard flat-colour edge produces a faint halo, which on a white background makes the box visible. Export as PNG, which is lossless.
Is anything uploaded?
No. The whole edit runs on a canvas in your browser.