Crop, watermark or blur part of a photo

When you need this

Somebody asks for a photo of your Ghana Card and you want the number covered. You are selling something and the picture has your gate and house number in it. You want to crop a document photo before sending it. These are small jobs that normally mean installing an app that asks for access to your whole gallery.

How to use it

1. Open the photograph.
2. Drag on it to mark the area you care about.
3. Crop to it, or blur it, or add a watermark across the picture.
4. Save the new copy. Your original is untouched.

Blurring properly matters

The blur here pixelates — it replaces the area with large flat blocks rather than smearing it. A soft smear can often be reversed well enough to read a card number back; blocks cannot, because the detail is genuinely gone.

This is also why covering something with a white box in a PDF is not the same thing. The box is a separate object sitting on top and anyone can move it. Here the pixels themselves are destroyed.

What to cover before you send a photo

• Ghana Card, passport and driving licence numbers, and the date of birth.
• Bank card numbers, including the last four, and the name on the card.
• Account numbers and reference numbers on statements and receipts.
• House numbers, gate colours, car number plates and landmarks in anything you post publicly.
• Other people's faces, especially children's, in anything going on social media.

What it does and does not do

• It works on one photograph at a time, in your browser.
• A watermark is a deterrent, not protection. Anyone determined can crop or clone it out.
• Location data hidden inside the file is a separate problem that cropping does not touch. Use remove the location hidden in my photo as well.

If something goes wrong

• The file got bigger. Re-saving an image can do that. Run it through fit my photo under a size limit.
• You need to cover something in a PDF. Take a screenshot of the page, blur it here, and rebuild the PDF — or blur before the document is made.