Glossary
XMP
XMP is an extensible, XML-based metadata format that can carry arbitrary fields, embedded in a file or kept alongside it as a sidecar.
Updated
Also written: Extensible Metadata Platform.
XMP was designed to be open-ended. Rather than a fixed list of tags, it is an XML packet in which any application can define its own namespace and write whatever it wants. That makes it the place editing software records develop settings, edit history, ratings and custom fields.
The open-endedness is exactly why it is worth checking. XMP can duplicate values already present in EXIF and IPTC, so removing one block can leave the same coordinates or the same creator name sitting untouched in another. A tool that reads only EXIF will report a file clean while an XMP packet is still carrying the information.
It can also live outside the image entirely, in a sidecar file next to it — which is how raw workflows keep the original untouched.
Related terms
- Sidecar file — A sidecar is a companion file holding metadata for an image that is left otherwise untouched.
- IPTC — IPTC is a metadata standard for editorial information — caption, creator, credit, copyright and keywords — rather than camera settings.
- EXIF — EXIF is the metadata standard cameras use to record how, when and where a photo was taken, stored inside the image file itself.