Hide private details in a screenshot, without uploading it
We share screenshots all day: a bug report for IT, a chat for a friend, a bank error for customer service, an example for an AI chatbot. Those images often show more than we meant: a phone number in the corner, a full name in a chat bubble, an email address in a header, an order number, a face in the background.
Many online "blur image" sites ask you to upload the picture first, which is exactly what you do not want with private information. This redactor runs entirely in your browser. The image is opened by your own computer, the boxes are painted onto a new copy, and the result is downloaded straight back. Nothing is sent to a server, and nothing is saved after you close the tab.
How to use it
- Add a screenshot: choose a file, drag it in, or paste it with Ctrl+V (Cmd+V on a Mac) right after taking it.
- Pick a style: black box, white box, pixelate or blur. For pixelate and blur, choose how strong.
- Drag a box over each thing you want to hide. Drag a box to move it, or drag its bottom-right corner to resize it. The style buttons also change the selected box.
- Download as PNG or JPG, or press Copy image to paste it straight into a chat or email.
Made a mistake? Undo takes back the last change, and the Delete key removes the selected box.
What to look for before you share
Private details hide in places people rarely check. Before you send a screenshot, scan it from corner to corner for these:
- Names and photos in chat headers, email "To" and "Cc" lines, and profile pictures of people in a group chat.
- Contact details: phone numbers, email addresses and home or office addresses, including in signatures.
- Numbers that unlock things: one-time codes, booking and order references, account and card numbers, even partly shown ones.
- The edges of the screen: browser tabs, bookmarks, the address bar, notifications that popped up, and file names in a taskbar.
- Reflections and backgrounds in photos: screens, whiteboards, documents on a desk, and car number plates.
If in doubt, crop the screenshot to just the part that matters before you add boxes. Less image means less to leak.
Which style should you use?
| Style | Best for | How safe |
|---|---|---|
| Black box | Passwords, card and account numbers, ID numbers, one-time codes | Safest. The pixels underneath are replaced, not covered. |
| White box | Documents and forms, where a black box looks heavy | Same as black. |
| Pixelate | Faces, number plates, backgrounds | Good for pictures. For short text, use Strong or a solid box instead. |
| Blur | Softly hiding busy backgrounds or other people's messages | The weakest of the four for text. Use Strong. |
Why can pixelated text be risky? Pixelation averages the colours inside each block. If the blocks are small and the text uses a known font, people have shown that it can sometimes be matched back to the original words. A solid box leaves nothing to match, which is why it is the right choice for anything you would not want read.
Your download is a clean copy
The downloaded image is drawn fresh from the screen pixels, so it does not carry over hidden photo data (EXIF), such as the phone model, the date it was taken or GPS location. The redacted areas are part of the image itself. They are not a layer someone could remove, which can happen when you "hide" things with shapes in a PDF or a slide.
How this tool was tested
Before it went live, I ran 57 automated checks on the publish version of this page, at phone width (375 px), in a Chromium-based browser. Last full test run: 17 October 2026.
- Every pixel of the black and white boxes was compared with the original, and the pixels outside a box had to stay unchanged. The test images were random noise made in the page, so any change shows up.
- Pixelate was checked against an independent calculation: each block has to equal the average of the original pixels, give or take 1.
- Blur was checked too, along with drawing, moving and resizing boxes with a mouse or a finger on a scaled-down canvas.
- Exports: the PNG download carries no EXIF data, and the download and copy functions were checked.
What the tests did not cover: the real clipboard and the real file-save dialog were replaced with stand-ins, so please check your own copy or download once. Blur and pixelate are weaker than a solid box for text, so use black or white for anything you must hide. Found a problem? Tell me on the Contact page.
FAQ
Is my image uploaded?
No. All the work happens in this page with the browser's own drawing tools. You can load the page, turn off your internet connection, and it still works.
Does it work on a phone?
Yes. Choose a photo or screenshot from your gallery and drag with your finger to draw boxes. On small screens, zoom out first so you can see the whole image.
Will the image lose quality?
Not with PNG. The download has the same size in pixels as the original. JPG is smaller but slightly softer, which is fine for photos.
Can I hide text before sending it to an AI chatbot?
For text you copy and paste, use our AI Privacy Mask tool, which swaps names, emails and numbers for placeholders and puts them back afterwards. For screenshots, use this redactor.