What EXIF Data Reveals, and How to Strip It

A JPEG is not only pixels. Alongside the image, your camera writes a block of metadata describing the circumstances of the photograph — and that block travels with the file into every email, marketplace listing and forum post you attach it to.

What is actually in the file

EXIF, and its companions IPTC and XMP, can include a great deal more than people expect:

• GPS coordinates, typically to a few metres, plus altitude and sometimes compass heading. This is the one that matters. A photo of a bike for sale can state the address it is stored at.
• Date and time of capture, often with time zone — a precise statement of where you were and were not.
• Device make, model and lens, plus firmware and, on some cameras, a serial number that links every photo you have ever published to the same body.
• Exposure settings — harmless, and the reason photographers do not want a blanket strip.
• Editing history and software, sometimes with the local file path, which leaks your username and folder structure.
• An embedded thumbnail. Occasionally the thumbnail was generated before you cropped the image, so it shows the part you cropped out.

Screenshots and scans carry their own version of this: device model, software, sometimes a filename that names a client.

What platforms do, and why it is not enough

Large social platforms usually strip EXIF on upload — partly for privacy, mostly to save bytes. Relying on that is a mistake for three reasons. It does not apply to email, to cloud links, to marketplace sites, to forums or to a file you hand over on a stick. It often does not apply to the original-quality download path. And the platform strips the data after receiving it, which does nothing about what the platform itself now knows.

The only reliable version is removing the metadata yourself, before the file leaves your device.

Removing it

The metadata remover here re-encodes the image in your browser without the metadata blocks, so the file that comes out has the pixels and nothing else. Nothing is uploaded, which is the only arrangement that makes sense: sending a photo to a stranger's server to have its location data removed is a strange way to protect its location data.

Two consequences to be aware of:

• Orientation. Many phone photos are stored rotated with an EXIF orientation flag telling viewers to turn them. Strip the metadata naively and the photo appears sideways; the flag has to be applied to the pixels first.
• Colour profile. Discarding an embedded profile can shift colours in a wide-gamut image. For screen use this rarely matters; for print work, keep the profile and remove only the location and device blocks.

Note also that resizing or compressing an image usually drops most metadata as a side effect, since the file is being written fresh. Convenient, but do not rely on it when the point is privacy — verify.

Habits worth having

• Turn off location tagging in your camera app unless you specifically want it. Not recording it beats removing it.
• Strip metadata before publishing anything from home, from a client site, or of a child.
• Rename files. IMG_4471.jpg says nothing; invoice-scan-acme-final.jpg says plenty.
• Check the result. Reopen the stripped file and look at its properties rather than assuming.

The same instinct applies to documents, where the author and producer fields are the equivalent leak — see redacting a PDF properly.