If you have ever edited a RAW photo and noticed a small file with the same name but an .xmp ending sitting right next to it, you have met an XMP file. It looks like clutter, but it is quietly holding your edits, star ratings, and keywords. Delete it carelessly and you can lose hours of work; understand it and it becomes one of the most portable things in your whole library. This guide explains what the XMP file format is, what lives inside it, which apps create it, and when you should keep, move, or delete a stray .xmp.
What is an XMP file?
XMP stands for the Extensible Metadata Platform. It is a metadata standard Adobe introduced in 2001 and later published as an open ISO standard (ISO 16684-1), so it is not locked to a single program. Under the hood, an XMP file is just plain text written as XML, which is why you can open one in any text editor and read it. That readability is the whole point: the format is designed so that many different applications can write and read the same descriptive information about a photo.
When people search for the XMP file type, they usually mean one of two things, and it helps to separate them:
- Embedded XMP. For formats that are safe to rewrite, such as JPEG, TIFF, PNG, DNG, and PSD, the XMP data is tucked inside the image file itself. There is no separate file to see.
- An XMP sidecar. For proprietary camera RAW files, editors avoid rewriting the original to keep it pristine. Instead they save the metadata in a companion .xmp file that lives beside the photo and shares its base name, for example DSC_0421.NEF paired with DSC_0421.xmp.
So a standalone .xmp file is almost always a sidecar for a RAW image. It is not the photo, and it is not a thumbnail. It is the notebook that travels with the photo.
What is XMP data, and what is inside the file?
Open an XMP sidecar and you will find labelled fields, often called XMP tags, describing the image. The exact contents depend on the app that wrote it, but a typical file from a photo workflow holds:
- Develop and edit settings. Non-destructive adjustments such as exposure, white balance, contrast, crop, and lens corrections. The original RAW is untouched; these instructions describe how to render it.
- Ratings and organisation. Star ratings, colour labels, pick and reject flags, and virtual copy information.
- Keywords and captions. The descriptive terms and titles you add to make photos findable later.
- Rights and contact data. Copyright notices and creator details, often mirrored from the older IPTC standard.
- Capture facts. Selected EXIF values and, where present, GPS coordinates.
In other words, an XMP file separates the description and treatment of a photo from the pixels of the photo. That separation is what makes RAW editing non-destructive, and it is also what makes metadata portable between programs.
Which apps create XMP files?
Most XMP sidecars you run into come from the Adobe ecosystem, but they are not the only source:
- Adobe Lightroom Classic. Lightroom keeps everything in its catalog, but it can also write a sidecar for each RAW file, either automatically (turn on Automatically write changes into XMP in Catalog Settings) or on demand with Metadata > Save Metadata to File. This is why a Lightroom user suddenly sees .xmp files appear next to their RAW photos.
- Adobe Camera Raw and Bridge. When you adjust a RAW file through Camera Raw, the settings are stored in an XMP sidecar so Photoshop and Bridge can read them back.
- ExifTool and similar utilities. Command-line and batch tools can read and write XMP directly, which is handy for bulk metadata jobs.
Capture One is a common point of confusion. It stores its adjustments in its own catalog or session rather than in XMP, but it can still read and write XMP metadata such as keywords, ratings, and copyright when you ask it to sync. So a .xmp sitting next to a file does not automatically mean Lightroom was involved, though it usually was.
Should you keep, move, or delete .xmp files?
This is the practical question behind most XMP searches, and the answer depends on what the sidecar is doing for you.
Keep them when the edits live only in the sidecar
If you edited a RAW file in Camera Raw or Bridge, the sidecar is the only record of those adjustments, ratings, and keywords. Delete it and the photo reverts to how the camera captured it. In that situation the .xmp is precious.
Move them together, always with the same name
A sidecar is linked to its image purely by matching base name and location. If you copy photos to a new drive or hand a folder to another person, move the .xmp files alongside their RAW files and do not rename either one. Split them up, or rename one and not the other, and the connection breaks silently. Our guide to adding metadata to photos covers how to keep that descriptive work attached to the right images.
They matter less for JPEGs
Because JPEG, TIFF, and DNG usually carry their XMP data embedded, a loose sidecar next to a JPEG is often redundant. It is safer to leave it, but losing it rarely costs you anything the image is not already storing itself.
Lightroom users have a safety net
If you work in a Lightroom catalog, your edits and metadata also live in the catalog database, so the sidecar is more of a portable backup than the single source of truth. That is a good reason to keep sidecar-writing switched on: it gives you a second copy that other apps can read. If you are moving away from Lightroom entirely, our notes on preserving catalog metadata during a migration are worth a read before you start.
The bigger goal: finding your photos again
Every XMP tag, keyword, and rating exists for one reason, which is to help you find a specific shot in a library that keeps growing. Sidecars are a good, standards-based way to store that information, but they still depend on you having entered keywords in the first place, and on every app in your chain reading them the same way. That is a lot of manual bookkeeping.
This is where a local-first tool changes the equation. Memora is a photo manager for Windows 10 and 11 that indexes photos where they already sit, with no re-upload. Two current capabilities are relevant to anyone wrestling with XMP metadata:
- Local AI semantic search. Instead of relying on keywords someone had to type, you describe the photo, "kids on a beach at sunset", and Memora finds it. All of that processing happens on your own computer, so it works even for the thousands of images you never got around to tagging.
- Native RAW and catalog support. Memora reads RAW files directly and can import existing Lightroom and Capture One catalogs, so the ratings and keywords you already built are not stranded. For how that compares side by side, see how metadata helps you find specific photos.
To be clear about the boundary: Memora is a Windows desktop application, not a cross-device cloud sync service. If your priority is owning and searching a large local library, that is exactly the job it is built for. A one-time Memora Pro upgrade (29.99 EUR) adds AI culling and face recognition for photographers who want them.
XMP files in one paragraph
An XMP file is a small, human-readable text file that stores a photo's edits, ratings, keywords, and rights information in Adobe's open Extensible Metadata Platform format. For most images the data sits embedded inside the file, but for camera RAW files it lives in a matching .xmp sidecar next to the photo. Keep sidecars when they hold edits you care about, move them together with their images and never rename one without the other, and remember that the whole point of all that metadata is simply to find the right photo when you need it.