All files contain hidden metadata. Images, documents, videos, audio files, e-books – there are no exceptions. In many cases, you are not aware of this hidden information since it can not be accessed at first glance. It is not obvious when you open or view a file, and even right-clicking the file and checking the details reveal only half of what there is to find.
With the right tool, however, everyone can check the metadata of your file. And this can be very scary! Many of us want to know exactly what they share with the world when posting a photo or video online. Thus, you should always check your file before uploading it to a public space or sending it out to someone else.
Even if this doesn’t scare you too much, aren’t you curious what information is stored in your file? Read on to find out!
What Can Hidden Metadata Tell Me?
First of all, what is metadata exactly? Easily said, it’S information stored in the header or background of the file that is not an active part of the file itself. The information is stored, yet does not appear in your picture or video, or can be heard in an audio file.
Usually, this information is created by the program used to create the file, the software it was edited with, recording devices like phones or cameras, and the computer you use to upload or open the file. Some metadata can even be added by the creator or user themselves.
While information such as file size, image dimensions, runtime or creator and file name is easily accessible on a computer, sensitive data might still be hidden out of view. Let’s see what kind of information that could be.
Have you ever seen the display of exif information on websites like flickr? They list all kinds of camera settings used for the images uploaded to the site. That way, amateur and professional photographers alike can see how a particular image was created with respect to mood and lighting.
This information is typically part of the camera raw image file, but also of the JPG or PNG image that the raw files have been turned into. This information includes, among others:
- auto focus
- and more
Location & Coordinates
Another piece of information often found in image files is the location where the image was taken. Depending on the information passed to the file, it is displayed as coordinates or address.
The location metadata is sometimes used in missing person cases. Other than that, it is generally used to determine the origin of an image. For example, if you see an image of a nice, scenic lakeside, by checking the metadata for the coordinates, you can find out where this place is.
Different kinds of date and time data are often stored in different files. While your viewfinder often shows the download date or the date you moved a certain file to a certain folder, a look into the hidden metadata can reveal even more.
This is especially interesting for version control of documents in particular. By looking at the last modification date of a document, you can easily determine which one you worked last on. This is especially useful if you work on an essay, thesis, presentation or other paper. In these cases, you often have the document stored in multiple places to access it from anywhere.
Yes, hidden metadata can be used to ensure the authenticity of a file. This can easily be applied to video and audio files, but also to e-book, document or image files.
Over the internet, it is possible that you get pirated versions of files – or even worse, files that are infected with a virus. While many people are, by now, aware of .exe and .zip files being potentially harmful, seemingly harmless document files with the .txt or .doc (Microsoft Word) extension can carry malware as well.
Metadata checks can be a way to reveal any suspicious information about the file. This is especially true for any kinds of author information, location, or even the system the file was produced in.
Share Only What You Want To Share
A factor that affects every one of us is personal security on the internet. By sending files via e-mail, uploading them to a website or providing them online as a download, we put out more information that we might be aware of.
In some cases, the information we share this way can be very sensitive. We don’t want everyone on the net to know where we work, live, go to school, etc. Thus, before sharing your file with a broader audience, check your files for such information!