When blur is the better choice
Blur reads as calmer than blocks, which suits family photos, school events and editorial pictures. At a strong radius it hides identity well; the strength slider here is the blur radius, and safety mode sets a floor relative to each face's size.
Blur has one weakness: a light blur is partly reversible by deconvolution. That is why the floor exists and why safety mode adds a faint grain over blurred areas. For anything with legal weight, choose square pixels or a solid bar.
Edges that don't give the game away
Ellipses fade over about a pixel at their edge so the blur sits naturally in the photo, while the face itself is fully covered. Padding grows each ellipse beyond the detected box to catch ears and hairline.
Questions
Is blurring a face as safe as pixelating it?
At a strong setting, for photos, it is effective. A weak blur can be partly sharpened again, so the page keeps the radius above a floor relative to each face and adds faint grain. For text or ID numbers use the solid bar instead.
How many faces can it find?
As many as the detector scores above its threshold — group photos with dozens of faces work. Each face can be switched off individually.
Can I blur faces in many photos at once?
Yes, on the bulk tool: drop a set of photos, the face finder runs on each, and you download a ZIP.
Does the face finder send my photo to a server?
No. Only the model file is downloaded (once, then cached). Detection runs in your browser tab.