Check a screenshot before you share it

What this check looks for

Data after the end of the picture

An image file says where its picture ends. Viewers stop there, but anything written after that point still travels with the file. In 2023, bugs in two widely used screenshot editors, one on phones and one on desktops, saved a cropped screenshot over the old file without removing the rest of the original, and researchers showed that the cropped-out part could be rebuilt. The check measures what comes after the end of the picture in PNG, JPEG and WebP files.

Location, device and names

Photos and some screenshots carry Exif and similar fields: where the picture was taken, the device and its serial number, the software, the date, and sometimes an author or a comment. They are invisible in the picture and readable by anyone who has the file. Screenshots taken on a computer rarely carry a location; photos from a phone often do.

Pixelated areas

Pixelation replaces text with blocks, and each block is the average of what was underneath. With the font and size known, that is often enough to get the text back, and public tools do it. The check finds areas that look pixelated and marks them, so you can cover them with a solid block instead. Our guide to hiding private information explains the research and lets you try the attack on a demo.

What it cannot check

• Blur. A blurred area looks too much like a soft photo or a shadow to flag reliably. If you blurred something private, cover it with Solid.
• Text in plain view. The check does not read the picture. Look at the address bar, tab titles, sidebars, avatars and notifications yourself.
• Other file types. PDFs and documents can hide the original under a box drawn on top. Send a flat image, or check the export with the tool that made it.

The clean copy

"Save a clean copy" makes a new picture from what you see and saves it as a new PNG, with your solid blocks burned in. The metadata, the location and anything after the end of the picture are not part of the pixels, so they stay behind. The picture itself does not change, apart from what you covered.

Nothing leaves your browser

The page reads the file with your browser's own file and canvas features. There is no server behind it: this site is a set of static files, and it loads no scripts from other sites. You can check this yourself. Open the developer tools (F12), choose the Network tab, then check an image: no request carries it anywhere. The counter under the tool reads the same list from your browser.

Common questions

Do screenshots contain my location?

Screenshots taken on a computer almost never do. Photos taken on a phone often do, and so can a screenshot that went through an app which adds its own fields. The check shows the coordinates if the file has them.

Does the check read the text in my image?

No. It reads the file structure and compares pixels to find the block pattern of pixelation. It does not recognise text, and it keeps nothing after you close the page.

Why is the clean copy a PNG?

PNG keeps every pixel exactly, so text stays sharp and the solid blocks stay solid. It can be larger than a JPEG of the same picture.