How to blur a face or number plate in a photo
Hide faces, licence plates and house numbers before you post a photo. Which method actually hides them, which can be undone and what else to check.
Photos posted online often include people and details that were never meant to be the subject: a stranger in the background, a child’s face, a car’s number plate, the house number behind you. Hiding them takes a minute, but the method matters, because some ways of hiding things can be undone.
Three ways to hide something
Blur softens the area so shapes are unrecognisable while the photo still looks natural. Right for faces in a crowd, backgrounds and anything where appearance matters.
Pixelate replaces the area with large blocks of colour. It is clearly deliberate and large blocks remove detail well.
Solid block covers the area with a flat colour. Nothing underneath survives and it is the only choice for text such as a plate number, a name or an address.
The redaction tool does all three. Draw a box over each area, choose the method and download a new image in which those pixels have been replaced. The original underneath isn’t kept anywhere in the file.
Why light blur isn’t enough for text
A slight blur or fine pixelation over a number plate can sometimes be reversed: try each possible plate, blur it the same way and compare. With few possibilities, the right one stands out. Heavy blur over a large area or a solid block, leaves nothing to compare against. The same principle applies to documents, covered in how to redact a document properly.
Check the rest of the picture
Faces and plates are the obvious details. Look again for house numbers, street signs, school logos, name badges, screens in the background and reflections in windows or glasses. Then check what the file itself carries: phone photos usually include the exact location. See should you remove EXIF data and strip it with remove EXIF. The redaction tool already removes all metadata from the image it saves.
Photos of other people’s children
Many schools, clubs and parents ask that children’s faces not appear online without consent. Blurring them or choosing a photo where they can’t be identified, respects that and avoids awkward conversations.
Common questions
Is blurring enough to hide a face?
For casual privacy in a crowd shot, a strong blur is enough. For someone who must not be identified at all, use a solid block: hair, clothing and build can still identify a person whose face is blurred and light blurs over small faces can sometimes be partly reversed.
Should I blur my number plate when selling a car?
Many sellers do. A plate can be used to look up vehicle details or clone plates. Blurring or blocking it costs nothing and buyers can see it in person.
Can someone unblur a photo?
Heavy blur and solid blocks can’t be undone, because the information is gone. Light blur and fine pixelation over text can sometimes be reversed by guessing candidate text and comparing. Use a solid block for anything like a plate number or a name.
What else in a photo can give away where it was taken?
Street signs, house numbers, shop fronts, school uniforms, reflections in windows and the location stored in the file itself. Check the whole picture and remove the metadata before posting.