Sharing may be caring, but sometimes your photos and screenshots show information—like your email address or your house number—that you want to keep private. Use these apps to hide them from prying eyes.

Black Out specializes in blocking out text in an image or PDF. Click and drag to create black rectangles over the areas you want to redact—no need to repeatedly select tools and colours. Drag and resize these “blackouts” to position them perfectly.

Black Out doesn’t alter your original image: Click the Export button to save the edited picture to a new file. You can also share your redacted image using the Share button.

Acorn’s Blur tool takes a subtler approach, obscuring information without screaming “I’m hiding something here!”

Follow these steps:

1. Choose the rectangular select tool from the Tools palette (or press M to enable the tool).
2. Draw a rectangle around the area you want to obscure.
3. Choose a filter from the Filter > Blur menu. Gaussian Blur is a safe bet, but experiment with the other options.
4. In the floating window that appears, choose the amount of blur to apply. You want just enough to obscure the info.
5. Choose File > Export to save a copy with your edits.

Cloaked automatically detects and obscures text, faces, or both. Simply drop a photo into the app’s window, choose which types of items you want to detect, and pick the type of filter: Black Out, Pixelate, Crystallize, or Blur; a preview to the right shows the results.

Fine-tune the results to strengthen the blurring or to add or remove text or face areas; then copy or export the resulting image.

The Preview app in macOS includes easy-to-use tools for obscuring information in images and PDFs. Follow these steps:

1. Click the Markup button (it looks like a pen tip) in the toolbar to bring up Markup tools.
2. Click the Shapes button and choose a shape that matches what you want to obscure.
3. Click the Fill Color button (it looks like a solid rectangle) and choose a colour that’s close to the hue of the area surrounding what you want to hide. The more similar the colours, the less conspicuous your blockout will be.
4. Drag and resize the shape on your image.

If you’re redacting content in a PDF, use File > Export to create a new document to share. (If you just save the PDF, someone could delete your shape and see what’s beneath it.)