What EXIF actually contains
EXIF (Exchangeable Image File Format) is a structured block of tags written by the camera at the moment of capture. A phone photo typically carries all of the following:
- GPS coordinates
- Latitude and longitude to roughly five metres, often with altitude and a UTC timestamp. Precise enough to identify a specific room in a building.
- Camera make and model
- The exact device — “Apple iPhone 15 Pro”, “Canon EOS R5” — which narrows who took a photo considerably in any small group.
- Capture software
- The OS or editing app version, useful for fingerprinting and occasionally for identifying unpatched software.
- Timestamps
- Both when the shutter fired and when the file was last modified, to the second, in local time.
- Body and lens serial numbers
- A hardware identifier unique to your specific camera. It links every photo you have ever published to the same physical device.
- Artist and copyright
- Often auto-filled with a real name by editing software, without the photographer noticing.
Where EXIF hides in JPEG and PNG
JPEG stores EXIF in an APP1 segment near the start of the file, introduced by the ASCII string “Exif” followed by two null bytes. Inside it sits a TIFF structure: a chain of image file directories holding tags, with GPS data in its own sub-directory.
PNG is widely assumed to be metadata-free, and that is wrong. PNG carries the same TIFF block inside an eXIf chunk, plus tEXt, zTXt and iTXt chunks that can hold arbitrary text, and a tIME chunk recording the last modification. A PNG exported from an editor frequently carries more identifying text than the JPEG it came from.
Because both formats wrap the same TIFF structure, the same tags leak from both — the container differs, the exposure does not.
Why “Save As” and screenshots don’t work
Re-saving a photo in most editors copies the EXIF block straight through. Cropping, resizing and colour adjustments all preserve it, because metadata is stored separately from pixel data and there is no reason for the editor to discard it.
Screenshotting does remove metadata, because you are capturing pixels rather than copying a file. But it re-compresses the image, drops it to screen resolution, and bakes in whatever the display was showing. It is a genuine fix that costs you the photo’s quality.
Stripping the metadata block directly removes the exposure and leaves the compressed image data untouched — byte for byte identical pixels.
What social platforms do and don’t strip
Most large platforms strip EXIF when they re-encode an uploaded photo, because they generate their own derivative sizes and the metadata does not survive that process. That is a side effect of their pipeline, not a privacy guarantee, and it does not apply everywhere.
Metadata routinely survives when a file is sent rather than uploaded: email attachments, messaging apps sending “as a file” or “as a document”, cloud storage links, marketplace listings on smaller sites, forum attachments, and anything you hand over on physical media.
The reliable approach is to clean the file before it leaves your device, rather than relying on each recipient’s pipeline to do it for you.
One tag worth keeping
EXIF Orientation is the exception. It is a display instruction, not identifying information: phones commonly store a portrait photo as landscape pixels plus a tag telling viewers to rotate it 90 degrees.
Strip that tag along with everything else and the photo renders sideways. It reveals nothing about you, so this tool always writes it back — every other tag you select is removed.