What is EXIF data, and what does it reveal about your photos?

What EXIF data is

EXIF (Exchangeable image file format) is information that a phone or camera writes into a photo file, next to the picture itself. You never see it on the screen, but it travels with the file wherever the file goes.

Other formats, called XMP and IPTC, do a similar job and are often added by editing and photo-management apps. People usually say photo metadata for all of it together.

What it can contain

• When the photo was taken, and sometimes when it was last changed.
• Which device took it: the make and model of the phone or camera, the lens, and the software on it.
• Camera settings such as exposure time, aperture, ISO and focal length.
• Where it was taken, as GPS coordinates, if location tagging was switched on in the camera.
• The orientation, so the photo is shown the right way up.
• Sometimes more: a small preview copy of the photo, a name or note, or a serial number that identifies one specific device.

Why the location is the part that matters

GPS coordinates in a photo can be accurate to within a few metres. A picture taken in your living room can point to your home address, and a picture taken outside a school or a workplace can show where someone is on a regular day.

The coordinates are plain numbers. Anyone who has the original file and a metadata viewer can read them and look them up on a map.

Who can see it

Anyone who receives the original file: an email attachment, a link to the original in a cloud folder, or a photo sent through a messaging app as a file or document.

Many social networks and messaging apps hide or remove location when you post a photo the normal way. How they behave differs from app to app and can change, so it is not safe to assume it. If you send the original file, assume everything in it goes with it.

How to see what is in your own photos

Use the photo metadata remover and viewer. Choose a photo and it lists what it found, grouped into location, personal details, device, date and camera settings. It runs in your browser, so the photo stays on your device.

Your phone’s gallery may also show some of these details if you open the photo’s info or details panel, but it usually shows only part of what is stored.

What metadata does not cover

Removing metadata does not change the picture. A street sign, a reflection in a window, a recognisable view or a face is still there. File names and the time you send the photo can also say something. Metadata is one clue among several, but it is the easiest one to remove completely.

What to do about it

1. Stop new photos recording where you are. How to remove location from photos on Android shows the setting to look for.
2. Clean the photos you already have before you send the original to someone, with the metadata remover.
3. Keep private photos out of the camera roll altogether in an encrypted vault. How to hide photos on Android compares the options.