What is EXIF data?
Whenever you take a photo with a digital camera, the camera embeds information about the shot into the photo, recording details such as time and date the picture was captured, camera model, camera settings, software used to edit the picture, and increasingly, location information gathered from the camera’s (or typically the smartphone with a camera) GPS hardware.
EXIF (Exchangeable image file format, more correctly shortened to Exif but we will use the more common if incorrect convention here) is the standard that specifies the format for this.
Reading Exif data
The simplest way to see at least a subset of the EXIF information contained in a picture is to use your OS’s built-in tools:
- Windows – right-click image file -> Properties -> Details tab (Win XP: Summary tab)
- OSX – Select image file in Finder -> Get Info -> expand the More Info section
- Unix – (GNOME) right-click image in Nautilius file manager -> Properties, (KDE) right click in Dolphin file manager -> Properties -> Information.
Why you want to remove EXIF data
Most of the information embedded in a digital photograph is harmless (although possibly of use to photography enthusiasts and students), but metadata dealing with time, date and location can constitute a serious breach of privacy, and can be used to identify the picture’s taker and his or her whereabouts. In December last year, for example, the FBI were able to trace and arrest fugitive computer security legend John McAffee in Belize thanks to EXIF data left on a photo he posted to his blog.
Also, Google have dropped hints about their use of EXIF data in their search engine ranking, and it seems reasonable to assume that the NSA hoovers up such information at a matter of course.
It is therefore a good idea to remove EXIF data from photos before you post them to the internet.
How to remove EXIF data
As noted, there are plenty of good tools for reading and editing EXIF data (QuickFix for Windows is a good example, as is ExifTool for Windows and OSX. Microsoft Pro Photo Tools is also a good option).
In Windows an even easier way, and one that requires no additional software, is to select all the images you wish to remove the data from (such as all those in a folder):
Right-click and select ‘Properties’, then click on the ‘Details’ tab and then click ‘Remove all Properties and Personal Information’.
You can verify that the information has been removed by right-clicking on the image file and selecting Properties -> Details.