How to Black Out Text in Photos
A photo of a document, a parcel, or a whiteboard — shared without thinking, it can hand strangers your name, address, or ID number. Black-box redaction fixes that permanently: solid pixels replace the sensitive areas, and the exported file contains nothing underneath to recover. Here is how to do it right, what to cover, and the mistakes that leak information anyway.
How to redact an image in three steps
- Add your photo. Open the Privacy tools page and drop your photo there or click to browse. It is read directly by your browser — sensitive documents never leave your device, which is the entire point of redacting locally.
- Draw boxes over every sensitive area: text, numbers, faces, plates, barcodes. Each box is listed below the image so you can remove one without starting over.
- Download. The exported file has solid black pixels baked in where your boxes were. The covered information is destroyed, not hidden — nobody can peel the boxes off.
Why solid black beats blur for real redaction
Blur and pixelation look safe, but light blur can sometimes be partially reversed — modern AI deblurring keeps getting better at guessing what was underneath. A solid black box has no information left to recover: every pixel is gone, verifiably. Rule of thumb: documents, IDs, and anything legal → black-box redact; casual privacy (a face in a crowd) → blur or pixelate is fine.
Common things people redact
- Mail and documents — names, addresses, account and ID numbers before posting photos of letters or paperwork.
- License plates — in car-sale listings, dashcam clips, and street photography.
- Screens — screenshots that caught private messages, emails, or dashboards in the background.
- Faces — especially children, or anyone who did not agree to appear in a published photo.
- Barcodes & QR codes — they encode data you probably did not intend to share.
Choosing the right shape and fill color
Three shapes cover nearly every situation. Boxes are the workhorse: fast to draw, easy to align with text lines, document fields, and license plates. Circles fit faces and round objects like stickers or badges better than a box, hugging the outline with less wasted coverage. Free-draw handles irregular shapes — a signature sprawling across a page, a tattoo, or a QR code printed at an angle — where neither a box nor a circle sits cleanly.
Black is the default fill for a reason: it reads unmistakably as "information removed" and photographs well in every context. But the color picker is there for practical reasons. White boxes blend into light documents and scanned paperwork, looking cleaner in a shared PDF. A custom color can match a brand background in marketing screenshots, or signal different redaction categories in legal review (black for privileged, gray for confidential, for example). The security is identical regardless of color — what matters is that the fill is fully opaque. Never use a semi-transparent highlight: anyone can boost the contrast underneath and read what you covered.
Redaction mistakes that leak information
- Covering only part of the sensitive text. A box that clips the edge of a name or number still leaves enough for guessing — "J_n Smith, 555-01__" narrows things down fast. Give every box a comfortable margin around the text.
- Forgetting the metadata. Blacking out an address in the pixels does nothing if the photo's EXIF data still contains GPS coordinates pointing at the same house. Strip the metadata after redacting — see our guide to removing EXIF data.
- Redacting a thumbnail or preview instead of the file you share. Some apps generate smaller previews; make sure the exported, full-resolution file is the one you checked. Open the download and zoom in before posting.
- Using the same box positions across a document set. If you redact ten pages of a contract and the boxes sit in identical spots, the layout itself hints at what was hidden. Vary placement where the surrounding content allows it.
- Trusting "blur" sliders inside other apps. Many built-in markup tools apply a light blur or a translucent marker that looks safe at a glance. If the stakes are real, re-do it with solid fills and verify at full zoom.