# XMP Sidecar Files Explained for RAW Photos > XMP sidecar files keep RAW edits beside the photo. See what they store, how the filename link works, and why edits vanish when the RAW and .xmp split up. - Canonical HTML: https://revelraw.com/blog/xmp-sidecar-files.html - Markdown mirror of this page: https://revelraw.com/blog/xmp-sidecar-files.md - Published: 2026-10-30 - Language: English - Machine-readable site index: https://revelraw.com/llms.txt · Full site as one file: https://revelraw.com/llms-full.txt Published October 30, 2026 · Daniel Tello · RevelRaw **Quick answer:** An XMP sidecar is a small XML text file named after the RAW (`DSC_0123.NEF` → `DSC_0123.xmp`) that sits in the same folder and stores metadata and develop settings while the RAW stays untouched. Edits seem to vanish when the pair is split, because the RAW was renamed, moved or copied without its `.xmp`, or when the app kept them only in its catalog. Keep each RAW and its `.xmp` together: same stem, same folder. An XMP sidecar is a small XML file, usually the same name as the RAW with a .xmp ending, that holds metadata and develop settings while the camera file stays untouched. You copied last night's card onto the desktop, opened the folder, and the frames look flat. Yesterday they had stars, a tighter crop, and a warmer white balance. The NEF and CR3 files are all there, and their sizes look right. What didn't come with them is the small companion that remembered the work. That companion is the second half of the photo. Treat the RAW and its matching XMP as one asset, and most "lost edit" stories turn into a naming problem, a catalog setting, or a file left behind. Each of those fails for a different reason, so you can tell which one you're looking at before you start the grade over. Edit RAW photos free on your Mac. RevelRaw · macOS 26 or later · Apple M1 or later [Try it on a RAW file](https://apps.apple.com/app/apple-store/id6773942240?pt=120914369&ct=BlogOutrank&mt=8) ## What an XMP Sidecar File Is Say the card just landed on the drive. Next to `DSC_0123.NEF` sits `DSC_0123.xmp`. Next to `IMG_0001.CR3` sits `IMG_0001.xmp`. The second file is tiny. It isn't a picture, and it isn't the preview JPEG the camera wrote for the back of the LCD. Open that `.xmp` in any plain-text editor. You're looking at a text document written in the **XMP** model, structured with **XML** and **RDF**. Named fields such as `xmp:Rating` or `crs:Exposure2012` show up as readable text. That's the fastest way to confirm the file holds instructions rather than pixels. ### What the text actually carries The document can hold author, copyright, keywords, ratings, and capture notes. It can also hold editing instructions such as exposure, white balance, tone, sharpening, and crop. [PicaJet's guide to camera RAW sidecars](https://picajet.com/articles/formats/camera-raw-sidecar-xmp/) notes that Adobe introduced the **Extensible Metadata Platform** in **2001** as a common framework for creating, processing, and exchanging metadata across publishing and imaging workflows. That model was later formalized as **ISO 16684-1 in 2012**. Many proprietary RAW containers can't safely accept arbitrary metadata writes, so the camera bytes stay put and the instructions live next door. The sensor file stays the negative. The sidecar is the editable half of a non-destructive pair. Before any export, RAW metadata has two homes, set by the workflow: a **same-folder sidecar**, or an **application database**. When you later save a processed file, that metadata can be embedded in the result. If you're also shaping a finished look, [photo color workflows from Image Studio](https://imagestudio.com/editorial/post/color-grading-photography/) sit beside this metadata half of the job. > The RAW is the capture. The sidecar is the memory of how you wanted it to look. See what RAW recovers on one of your own photos. Pull back blown highlights and lift the shadows on a RAW you already have. Your first full-quality export is free. macOS 26 or later · Apple M1 or later [Try it on a RAW file](https://apps.apple.com/app/apple-store/id6773942240?pt=120914369&ct=BlogOutrank&mt=8) ## What the Sidecar Stores Apart from the RAW The camera file and the text file don't share the work evenly. One row of a folder can look complete while the look you made lives somewhere else entirely. | Information | Camera RAW | XMP sidecar | App catalog | | --- | --- | --- | --- | | Sensor image data | Yes, left unchanged | No | No | | Exposure, white balance, tone, sharpening | Not rewritten into the RAW | Yes, as develop settings | Copy only if the app stores one | | Lens corrections | No | Often | Only when that catalog records them | | Crop and straighten angle | No | Yes | Sometimes | | Ratings, keywords, copyright | Sometimes already in EXIF or IPTC | Yes | Often | ### Pixels stay in the camera file **Sensor image data** lives only in the RAW. A normal develop pass doesn't rewrite those bytes. Lift exposure by one stop and change the copyright line, and neither the NEF nor the CR3 changes byte for byte. The picture on screen changes because the app is reading instructions, not because the capture was resaved. **Exposure, white balance, tone, and sharpening** are develop settings in the sidecar. The RAW row stays "not rewritten" on purpose. If the catalog also keeps a copy, that copy is a second record, not a replacement for the text file on disk. ### Instructions that aren't a new picture **Lens corrections** usually travel as sidecar instructions rather than baked pixels. A catalog may record them too, but only when that app is set to keep its own copy. **Crop and straighten angle** travel the same way. The sidecar remembers a rectangle and an angle. It does not contain a cropped pixel file you could open on its own. Delete the sidecar and the full sensor frame is still there, uncropped. **Ratings, keywords, and copyright** can be written to the sidecar even when the camera already embedded some EXIF or IPTC. The camera's embedded block and the sidecar's copy can disagree after you edit. The sidecar is the one your current app is more likely to trust once it has written there. A careful pass with a [photo metadata editor](https://revelraw.com/blog/photo-metadata-editor.md) is how you see which block changed. ### Three stores, three jobs An application catalog may hold a second copy of the same instructions, and it can be the only copy if sidecar writing is off. That is a different job from the file next to the RAW. - **RAW:** the pixels, left alone. - **Sidecar:** portable instructions you can copy with the photo. - **Catalog:** the app's private index, useful on that machine and invisible to a folder you hand someone else. Exporting a finished file is a later step. Until then, these three stores don't stand in for each other. ## How the Filename Keeps the Pair Together In the Adobe convention, the sidecar uses the RAW's base name and sits in the same folder. There is no hidden object ID inside a typical proprietary RAW that points at the companion. Apps rediscover it by stem and location, which is why a pair that looks obvious to you can be invisible to the software. Adobe's XMP specifications describe that sidecar as an XML metadata document stored apart from the RAW, using the image's base filename in the same directory, as with `IMG_0001.CR3` and `IMG_0001.xmp`. The split keeps arbitrary writes out of containers that can't safely take them. ### Three pairs that match Everyday **XMP sidecar files** written by Adobe-style apps follow one pattern. - **`IMG_0001.CR3` and `IMG_0001.xmp`:** Canon stem, same folder. - **`DSC_0123.NEF` and `DSC_0123.xmp`:** Nikon stem, same folder. - **`A7_2044.ARW` and `A7_2044.xmp`:** Sony stem, same folder. Change the stem on only one of them and the match is gone, even if both files are still on the disk. darktable is the exception: it appends `.xmp` to the whole filename, so `IMG_0001.CR3` gets `IMG_0001.CR3.xmp`. RawTherapee doesn't use XMP for its edits at all; it keeps them in a `.pp3` sidecar. ### What breaks the match A rename of only the RAW breaks the stem. `DSC_0123.NEF` renamed to `portrait-0123.NEF` no longer belongs to `DSC_0123.xmp`. A move of only one file breaks the folder match. The names can be identical and still fail if one file is in `Selects` and the other stayed in `Card Dump`. `DSC_0123.XMP` versus `DSC_0123.xmp` can fail on a case-sensitive volume even when a Mac folder looks fine to the eye. The letters match. The case doesn't. A second copy of the RAW in another folder doesn't inherit the sidecar unless that copy is present too. Some asset systems allow more than one associated sidecar for a single image, and a database can index many images in one place, so "the" sidecar is a workflow choice. For most Adobe-style readers, one photo, one stem, one folder is the everyday contract; darktable appends `.xmp` to the whole filename instead. > **Practical rule:** Before you trust what an editor shows, confirm in Finder that the RAW and the `.xmp` share a stem and a folder. Import, export, and batch work should treat that pair as one asset, keep case-insensitive `.xmp` discovery where the volume allows it, and warn you when a sidecar is absent or newly changed. ## How Editing Apps Store and Share Sidecars Writing an XMP sidecar and keeping a private catalog are different decisions. An app can do one, the other, or both. A folder that looks edited in one program can look untouched in the next because of that choice, not because the grade was deleted. | Editor | Default store for RAW edits | Sidecar behavior | What another app usually gets | | --- | --- | --- | --- | | Adobe Camera Raw and Bridge | Same-folder XMP by default | Writes stem.xmp next to the RAW unless set to the Camera Raw database | Ratings, keywords, and many develop settings when the reader understands Adobe XMP | | Lightroom Classic | Catalog | Writes stem.xmp for proprietary RAW only when Automatically Write Changes into XMP is on or you choose Save Metadata to File; DNG, JPEG and TIFF get the XMP inside the file | Nothing portable until that write; then a partial Adobe XMP | | Capture One | Session or catalog settings files | Syncs ratings, color tags and keywords with XMP when Auto Sync Sidecar XMP is on | Metadata yes when sync is on; develop look no | | darktable | XMP sidecar | Writes its own XMP beside the RAW, named IMG\_0001.CR3.xmp | Little; Adobe-style readers look for the bare stem, and the edit history uses darktable's own namespace | | A catalog-only editor | Private database | No sidecar unless exported | Nothing from the folder alone | ### What actually travels **Adobe Camera Raw and Bridge** park develop settings in a same-folder `.xmp` by default, so the RAW stays portable. That comes from the Camera Raw preference "Save image settings in", which is set to Sidecar .xmp files; switch it to the Camera Raw database and the settings stay on that Mac instead. Copy the pair and a reader that understands Adobe XMP can pick up ratings, keywords, and many develop settings. **Lightroom Classic** keeps the working record in its catalog and writes XMP only when you ask it to: turn on Catalog Settings > Metadata > "Automatically Write Changes into XMP", or select photos and choose Metadata > Save Metadata to File (Cmd-S). For a proprietary RAW such as a NEF or CR3, that write creates a sidecar. For DNG, JPEG, and TIFF, the XMP goes inside the file itself. That's why a catalog can show stars that a freshly copied folder doesn't. Until that write happens, the other machine gets nothing from the folder alone. After it, the handoff is still a partial Adobe XMP, not a full clone of the catalog. **Capture One** keeps adjustments in its own session or catalog settings files. It can sync ratings, color tags, and keywords with XMP sidecars when "Auto Sync Sidecar XMP" is enabled in its metadata preferences, but it doesn't read Adobe develop settings. The metadata can travel; an Adobe develop look doesn't. **darktable** writes an XMP sidecar beside the RAW, but it names it after the whole filename, as in `IMG_0001.CR3.xmp`, and stores its edit history in its own namespace. An app that looks for `IMG_0001.xmp` won't find it, and a full darktable look doesn't transfer to another editor. A catalog-only editor never puts a sidecar in the folder unless you export one. The folder by itself has no edit to read. ### A limit that sits on every row A readable sidecar isn't a guarantee of identical rendering. Profiles, masks, and local adjustments are often specific to the app that wrote them. Another program can honor the exposure and still draw the photo differently. Ask one question of any new editor. Does it read the sidecar already on disk, or only its own database? ## Why Ratings or Edits Seem to Vanish The file is rarely corrupt. A RAW that looks reset is usually a photo whose instructions are somewhere else. Read the symptom, then match it to one cause. | What you see | Usual cause | What is still true | | --- | --- | --- | | Ratings gone after a copy | RAW copied without the matching .xmp, or catalog was the only store | Sensor data is intact | | Edited in one app, flat in another | Sidecar never written, or the reader ignores that namespace | The first app may still hold the look | | Crop arrives, masks do not | Only shared fields were readable | Local edits were app-specific | | Sidecar visible but ignored | Extension case, a different folder, or a naming convention the reader doesn't expect | The stem rule failed | | Two copies disagree | Each folder has its own sidecar | They are no longer one asset | ### The five tells **Stars and keywords gone in a new folder.** Yesterday's picks are absent after the copy. The catalog, or a sidecar you left behind, still holds them. The RAW alone never did. Sensor data is intact. **Edited in Lightroom, flat somewhere else.** The same folder looks finished in one app and untouched in another. Either Lightroom never wrote XMP, or the second app isn't reading that namespace. The first app may still hold the look. Re-grading from zero throws away a record you haven't found yet. **A crop appears and the masks don't.** Basic adjustments traveled. App-specific local edits didn't. Shared fields were readable. The brush work was not part of that shared set. **The sidecar is on screen and the editor ignores it.** A Linux backup or a case-sensitive disk shows the RAW and a `.XMP` that the Mac editor skips. The stem matches to the eye and fails on case, or the two files aren't in the same folder. A darktable sidecar named `IMG_0001.CR3.xmp` is skipped by readers that look for `IMG_0001.xmp`. **Two copies disagree.** Each folder has its own sidecar, so they are two assets now. Editing one doesn't update the other. ### Separate this from a broken RAW If the embedded preview still opens, the capture is intact and only the instruction file or the database is out of reach. Metadata can remain only in the sidecar or the catalog until a processed derivative embeds it. > Look for the matching stem in the same folder before you re-edit the photo. ## The RAW Plus Sidecar as the Archive The file you still want in ten years is not "the RAW, probably." It's the original RAW plus its matching sidecar, same stem, consistent case, and a backup of both. The sidecar is a separate text file, so it can move with the RAW to another drive or another compatible app without rewriting the capture. [Adobe's metadata overview](https://www.adobe.com/digitalimag/pdfs/about_metadata.pdf) describes that portability directly: photographers can preserve the original RAW, copy the RAW-plus-XMP pair, and transfer descriptive metadata or non-destructive adjustments between compatible applications. Keeping metadata in an XML sidecar beside an untouched original is a common archiving arrangement for the same reason. Think of a sealed negative with a caption card clipped to the sleeve. The negative stays sealed. The card travels with it. ### What a "complete" drive can still lose A drive holding only NEF, CR3, ARW, or RAF files can look complete by file size and still have lost ratings, keywords, copyright, and develop instructions. Adobe warns that metadata may remain only in the sidecar or an application database until the RAW is rendered into a processed format. If the RAW moved without its matching `.xmp`, those fields appear to be missing even though the pixels are fine. Each source image may have one or more associated sidecars, while a metadata database can hold records for many images in one place. That database is not a spare copy unless you back it up on purpose. When you compare backup and storage options, treat the pair, or the catalog you chose instead, as the unit that has to survive the copy. A [storage calculator for RAW libraries](https://revelraw.com/raw-storage-calculator.md) helps you size the disks, and it won't warn you if the sidecars were left out of the set. ### The export boundary Once the image is rendered to JPEG, TIFF, HEIF, or processed DNG, chosen metadata can be embedded in that derivative. The derivative is a new file, not a substitute for the RAW pair. Until that render, the sidecar or the catalog remains the only record of the edit. Check a backup set this way. Every RAW you care about has its `.xmp` beside it, or you have consciously chosen a catalog as the only record and you back that catalog up with the same care as the photos. ## Choose a Sidecar Workflow on Your Mac The earlier facts collapse into three branches. Pick the one that matches how the photos have to travel. **Photos must open with the same ratings and basic develops on another machine.** Write sidecars and keep each `.xmp` beside its RAW. The folder is then the asset. A catalog on the first Mac is optional, not required. **One catalog is the only place you edit.** Accept that the folder alone will look unedited. Back up that catalog as carefully as the photos. A drive full of RAWs is not a copy of the work. **You're leaving a Lightroom catalog.** Don't expect the catalog file itself to travel. RevelRaw doesn't import the Lightroom catalog. Write the XMP first (Metadata > Save Metadata to File), then move the photos with their sidecars, or with a DNG export that embeds metadata, and check the result in the destination app. RevelRaw reads supported Lightroom adjustments, including the crop and straighten angle, from a DNG or an accessible XMP sidecar beside the RAW. Adobe profiles and masks are not imported, and rendering can differ. For a Mac workflow that stays on one machine, RevelRaw is one editor to test. Open a copy of a folder with its sidecars and confirm that the crop and basic adjustments appear before you rely on it. A [RAW photo editor for Mac](https://revelraw.com/blog/raw-photo-editor-for-mac.md) only helps if it reads the file that's on disk. The practical next step is small. Pick one folder, confirm each RAW has a matching `.xmp` if you depend on sidecars, and open that folder in an editor that reads the sidecar rather than assuming a catalog will follow. See what RAW recovers on one of your own photos. Pull back blown highlights and lift the shadows on a RAW you already have. Your first full-quality export is free. macOS 26 or later · Apple M1 or later [Try it on a RAW file](https://apps.apple.com/app/apple-store/id6773942240?pt=120914369&ct=BlogOutrank&mt=8) ## Frequently Asked Questions ### What is an XMP sidecar file? An XMP sidecar is a small XML text file stored in the same folder as a RAW photo, usually with the same name and a .xmp ending, so DSC\_0123.NEF is paired with DSC\_0123.xmp. It holds metadata such as ratings, keywords and copyright, plus develop settings such as exposure, white balance and crop, while the RAW file itself stays unchanged. ### Can I delete .xmp files? You can, and the RAW pixels won't be harmed, but anything stored only in that sidecar goes with it: ratings, keywords and edits. The photo then opens unedited. If your editor also keeps a catalog, it may still hold a copy; if it doesn't, the sidecar was the only record, so back it up instead of deleting it. ### Why did my Lightroom edits disappear when I copied the folder? Lightroom Classic keeps edits in its catalog and writes them to XMP only when Automatically Write Changes into XMP is on or you choose Metadata > Save Metadata to File. If neither happened, the copied folder has no sidecars to read. If the sidecars do exist, check that each .xmp was copied with its RAW and still shares its stem and folder. ### Does Lightroom Classic write XMP sidecars automatically? Only if you turn it on, in Catalog Settings > Metadata > Automatically Write Changes into XMP. Otherwise, select the photos and choose Metadata > Save Metadata to File (Cmd-S). For proprietary RAW files such as NEF, CR3 or ARW it writes a .xmp sidecar; for DNG, JPEG and TIFF it writes the XMP inside the file. ### Can RevelRaw read Lightroom XMP sidecars? Yes, for supported adjustments. RevelRaw reads them from a DNG or an accessible XMP sidecar beside the RAW, including the crop rectangle and straighten angle and, since version 4.8, HSL. Adobe profiles, Lightroom masks and catalogs are not imported, and rendering can differ. RevelRaw also writes star ratings to RAW .xmp sidecars for Lightroom and Bridge. * * * RevelRaw is a native Mac RAW editor that reads supported adjustments from an XMP sidecar sitting beside the photo, including crop and straighten, while leaving your camera files on your machine. You can check a copied folder's crops and basic develops without importing a Lightroom catalog or signing in. It also writes star ratings to RAW `.xmp` sidecars that Lightroom and Bridge can read, and it requires macOS 26 or later on an Apple M1 or later Mac. Visit [RevelRaw](https://revelraw.com) and open one folder that already has its sidecars to see which of those instructions come across.