Blur faces in a photo

School events, team photos, a protest, a street scene with strangers in the background: before a photo goes on social media or into a newsletter, the faces of people who did not agree to be posted often need to go. Many parents blur their children’s faces on public accounts, and schools and clubs ask for it when some families opt out. The irony of most face-blurring websites is that they want the unblurred photo uploaded to their server first.

Here the photo opens in your browser and stays there. As soon as it loads, a face detector running in the page marks every face it can see; drag a box over any it missed. The blur appears straight away, and each box has a × in its corner to remove it. On a phone, drag with one finger. The blur reads the pixels around each box so the edge fades into the photo instead of looking like a pasted rectangle.

For a face that must not be recognised at all, push Strength up until the preview shows only a soft patch of skin tone, or switch the effect to Pixelate or Black box. Hair, a distinctive jacket or a name badge can identify someone as surely as a face, so cover those too. The saved photo is written without its location and camera data, which a posted photo of children should not carry anyway.