EXIF metadata: what your photos reveal

The photo is a document with a dossier

EXIF stands for Exchangeable image file format. It is the standard that describes how a camera records information about the capture inside the image file itself. Today it is maintained jointly by CIPA and JEITA under the CIPA DC-008 specification, the current version is Exif 3.0, published in 2023, which added UTF-8 text support. In a JPEG, this data lives in an application segment called APP1 (marker 0xFFE1), right at the start of the file; in a TIFF, it sits in image sub-directories (IFDs) pointed to by a private tag. Either way, the bytes travel glued to the pixels: whoever gets the original file gets the dossier.

The best way to understand is to read a real metadata dump. Below is a reading in the style of the exiftool utility, the values are made up, but the format is exactly what a common smartphone produces. Notice how many lines describe you, not the photo.

$ exiftool DSC_04821.jpg      # exemplo ilustrativo, valores ficticios

Make                : Apple
Camera Model Name   : iPhone 14 Pro
Lens Model          : iPhone 14 Pro back triple camera 6.86mm f/1.78
Software            : 17.5.1
Date/Time Original  : 2026:03:14 18:42:07        <-- quando / when
Exposure Time       : 1/120
F Number            : 1.8
ISO                 : 64
Orientation         : Rotate 90 CW              <-- como foi segurado
GPS Latitude        : 40 deg 44' 54.36" N       <-- onde / where
GPS Longitude       : 73 deg 59' 08.36" W
GPS Altitude        : 11.3 m Above Sea Level
GPS Date/Time       : 2026:03:14 22:42:05Z
Serial Number       : (alguns corpos gravam; MakerNote)
Thumbnail Image     : (Binary data 8734 bytes)  <-- miniatura embutida

Three lines say when (Date/Time Original), where (GPS) and with what (Make, Model, Lens, Serial Number). Together they turn a cat photo into a stamp of time and place. And EXIF is not the only possible metadata container inside an image, just the most common one in cameras.

EXIF

Capture metadata written by the camera: date, settings, lens, orientation and GPS. The focus of this guide.

IPTC

A photojournalism standard: caption, credit, keywords, headline. Describes the content, not the machine.

XMP

Adobe’s XML wrapper (2001). Holds edits, notes and copies of EXIF/IPTC fields under namespaced names like dc:creator.

What exactly rides along

Not every field is sensitive: aperture (F Number) or exposure time interest photographers and no one else. The problem is the fields that point back at you. The table gathers the most revealing ones.

The coordinate is not stored as a friendly decimal number. GPS lives in its own sub-directory, the GPS IFD, with dozens of standardized tags: latitude and longitude go in as three fractions, degrees, minutes and seconds, plus a reference tag (N/S, E/W) and another for altitude. Worked example: a latitude stored as [40/1, 44/1, 5436/100] means 40 degrees, 44 minutes and 54.36 seconds. Converting, 40 + 44/60 + 54.36/3600 = 40.7484° N, a precision of a few meters, enough to land on your front door on a map.

The Orientation tag explains an everyday mystery. The sensor always records pixels in the same physical direction; when you turn the phone to portrait, it does not rotate the matrix, it just writes a number from 1 to 8 telling the viewer how to rotate or mirror the image. Value 6, for instance, means “rotate 90° clockwise”, the most common case for a vertical phone photo. If a program ignores that tag, the photo shows up sideways. It is harmless metadata, but it shows clearly that the image you see is already an interpretation of the bytes, not the raw bytes.

Where this habit came from

Embedding data inside the photo is old, but geolocation by default is recent, and it came from convenience, not surveillance. The timeline shows how we got here, and where the movement now points.

1. 1995Exif 1.0 (JEIDA)

   The first version of the standard defines the image format and attribute tags, maker, model, date and capture settings.

2. 1997–1998GPS enters the standard (Exif 2.x)

   The Exif 2.x line adds the sRGB color space, compressed thumbnails and the GPS IFD, the compartment that would later carry coordinates.

3. 2001Adobe’s XMP

   Adobe introduces XMP, an XML wrapper for metadata that editing software uses to record authorship and history alongside EXIF.

4. 2008 onwardThe GPS smartphone era

   GPS phones (starting with the iPhone 3G, 2008) make geotagging a default: billions of photos are now born with coordinates, most without the owner noticing.

5. 2021–2024C2PA / Content Credentials

   A coalition (Adobe, Microsoft, BBC, Google, Sony and others) standardizes cryptographically signed provenance metadata, the opposite movement: instead of hiding the origin, proving the origin.

C2PA deserves a paragraph because it inverts this article’s logic. Where EXIF is passive metadata you want to remove, Content Credentials is active, signed metadata you may want to keep: it records origin and edit history in a manifest that, once signed, exposes any later tampering. It is the difference between a dossier that leaks your location and a seal that proves where the image came from, useful in the age of AI-generated images.

What platforms strip, and what they do not

The good news: most large social networks re-encode the image you upload, to compress and standardize it, and that re-encoding throws EXIF away as a side effect. Facebook, Instagram, X and others publish the clean version to the public. The bad news has three parts. First: that is a consequence of compression, not a privacy guarantee, and policies change without notice. Second: “stripping the public version” is not the same as “deleting”; several platforms keep the original file, with all its EXIF, on their own servers. Third: there are shortcuts that preserve everything, sending a photo as a “document” or “file” instead of an image usually skips compression and delivers the untouched original on the other end.

Keep in mind the photo is not the only leak in a post. The IP address of the connection that made the upload also identifies your network, the public vs. private IP guide explains what it reveals and what it does not. Image metadata is just one of the layers.

Why deleting EXIF is not anonymity

Here is the fine point almost every tutorial forgets: removing EXIF cleans the label, not the image. A photo with no metadata still carries, in the pixels themselves, enough information to locate and identify. Four residues survive the cleanup, each one demolishes the idea that “I stripped the EXIF, therefore I am anonymous”.

How to remove metadata for real

Safe removal has four steps, and the one most people skip is verification. Trusting a “remove metadata” button without checking the result is like closing the door without testing the handle.

1. Verify firstOpen the photo in an EXIF reader and see what is there: GPS? date? serial number? embedded thumbnail? You cannot safely remove what you do not know is present.
2. Remove by re-encodingRe-encoding the image (redrawing it into a new file) discards the whole EXIF block, including GPS and the thumbnail. It is more reliable than deleting tag by tag, because it leaves no residual container behind.
3. Verify again, including the thumbnailReopen the clean file in the reader. Confirm GPS, date and serial are gone and that there is no embedded Thumbnail Image. This is the step that closes the thumbnail leak.
4. Remember the copiesCleaning the new file does not erase versions you already shared. If the original leaked, treat it as public, removal protects the next post, not the previous one.

One last useful framing: metadata is not the same as the image, just as a hash is not the same as the data it summarizes. If that border between “the content” and “what describes the content” interests you, the hashing, cryptography and encoding guide works the same idea on different ground. In the end, image privacy is deciding, consciously, what stays inside the file before it leaves your hand.