What EXIF and file metadata actually reveal about you, and why you should strip it before sharing files.
What is metadata?
Every file you create carries more than what is visible to you. Be it documents, images, audio files all of them contain a block which includes technical data alongside the actual content that you see. For example how do that software you used know at exactly what time your photo was taken. It is because of metadata. Most people never look at this. So most of the time this does not get removed.
In photos, this is called EXIF (Exchangeable Image File Format). Depending on the device, it can include camera model and make, the exact date the photo was taken, exposure and lens settings, and sometimes if enabled exact GPS coordinates of where the photo was taken.
Documents also carry their own version of this. Author name, the computer’s username, software version, sometimes the full editing history of the document. This mostly happens in
.docxand.pdfby default.
Why it matters more than we think?
None of this shows up when you open a file. That’s what makes it dangerous. It sits there until someone runs the right tool on it.
For example imagine,
- The photo you took from home includes exact Geo-location of your home. Cropping something out of the frame or blurring does not remove it. These coordinates live in metadata not in the pixels you see.
How to remove it?
The easiest way to prevent this is by stripping down metadata of things you share. Not from everything, just the ones you think it is better to remove before sharing. For removal you can use tools such as exiftool or mat2.
