Feature request: Carry and backup raw developer sidecar files

It would be nice, if Mylio would carry the sidecars of external raw developer (e.g. DxO Photolab or ON1 Photo RAW) with the raw files during file operations.
Having those files backed up with Mylio would also be a great benefit (not having to take care of a backup separately of an already backed up folder)
Either gather the most common sidecar extensions or let the list being user editable ín the settings.


For these sidecar files - do they have the same filename as the .JPG or RAW files?

If so, do you expect in the Mylio UI that they are bundled with the image Media, so that if you move the Media tile inside Mylio from one folder to another it moves both the image and sidecar in the File System? (Like we currently do for .XMP’s?)

Or should these be separate tiles in Mylio that you can independently move & delete?

Yes, have the same filename, although there exist two naming schemes:
filename.sidecar_extension or

I would like to have these sidecar files handled exactly like you do with the .XMP files now (except that you don’t have to edit them of course).

At the moment, when I move/rename a complete folder, you move them along.
When I delete all photos from a folder (cleaning up), then you cannot delete the folder inside Mylio because of these files.
When I move some already edited photos to another folder, I have to move these files along by hand in Explorer to not loose the edits I have done.
And now I have to back up these files manually, although Mylio backs up excellently everything else in the folder, where these files are.

Here are some examples from the 3 raw developer on my computer. Other programs might have other extensions.

2019_12_30_9999.CR3.dop -> DxO Photolab sidecar

2019_03_31_IMG_1423.on1 -> ON1 Photo RAW sidecar

IMG_20200107_164426_45-1.dng.pp3 -> RAW Therapee sidecar

There are other programs, which use .EXT.XMP as sidecar (e.g. Darktable), but I think you already handle them.


I would like sidecars created by Exposure X to be carried as well, and moved with the images. They keep them in a sub-folder hierarchy below the folder with the images, with the same name as the image including the extension, and then .exposurex5 added (the number changes with each new major version). The top sub-folder is called ‘Exposure Software’ and the next is currently ‘Exposure X5’ - this also changes with new software versions. Exposure Software used to be called Alien Skin, and that can appear on older systems as a folder name at the top level too.

Pictures (folder)

Exposure Software (sub-folder at same level as image)

Exposure X5 (sub-folder)


I second this feature request. It is mandatory for any DAM to work seamlessly with other RAW converters.


Seconding this request. It would make it much easier to work with editors that don’t have xmp sidecars. DxO is a major one and it’s disappointing that it’s not supported in this way.

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I’d like to request you sync CaptureOne Pro files to enable C1 editing on multiple machines.

There are two ways this could be done. One way is to require the Captureone Pro user to use “Sessions” mode (C1 works as a catalog or in Sessions mode) and simply sync the CaptureOne *.cosessiondb file whenever you see it.

Another way would be to sync the /CaptureOne sub folder which C1 creates when it opens a folder of images (and no .cosessiondb file is present). In my view it would be good to do both. The .cosessiondb file contains the previews and all edit instructions for non-destructive editing in one package. If it doesn’t exist, C1 stores all edit info (.cos files) and previews (*.cop) files in the /CaptureOne subfolder structure.

Session Only approach. Support this one file:

  • .cosessiondb (this is a database file that tracks all the images in a folder and contains preview and adjustments).

The more inclusive approach would be to sync, additionally, the extensions found in the folder structure beneath \CaptureOne are:

.cos files contain all adjustment information

  • .cop files (these are image previews. Ideally Mylio would recognize these and use them for it’s own previews as they would reflect all edits. That’s a big ask but what a win that would be … to display the C1 edited rendition of the image rather than an un-editied straight raw conversion.

  • .comask files . These are used by C1 for layer masks

  • .cot files. These are thumbnail files and they are probably no necessary as C1 will regenerate them if they are not there. That said, they are tiny so why not?

  • .cof files. These are focus mask files

  • .ICM files (custom ICC profiles)

Most of these files are tiny with the exception of the .cosessiondb file (if Sessions were used) and the .cop files which are image previews.

More info can be found here


This would be great improvement to already great app/engine, count me in for DxO (.dop) … sidecar should be handled as one (bunddled) file together with original source file. Kind a mandatory behavior for DAM.

Thank you in advance for consideration .-)

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Still no progress after almost a year. :slightly_frowning_face:

You advertise Mylio as a vial backup solution by using Mylio Vaults, which doesn’t work for anyone using external editors, that store their edits in non-xmp sidecar files. Also the ability to reedit my photos on every machine that syncs the originals breaks, if the sidecar files are not synced.

I really don’t understand, why this is not a high-on-your-list feature to implement, at least for the top 3 editors LR, C1 and DXO. And it would be so easy to implement. Just a few additional file extensions that sync along with the picture and xmp files.

Just to get my iPhone snaps to all my devices, I don’t need Mylio. iCloud is cheaper and I get all the goodies of Photos machine learning, like the ability to find picture content without prior tagging.
I need Mylio as a DAM with device syncing for the shots with my real cameras and they usually are worked on in DXO or other advanced editors.

If Mylio doesn’t get this sidecar-files syncing sorted out soon, I’d need to look elsewhere.


Very good point, please consider this as a priority … because there would not be to many reasons to stay with Mylio without proper implementation of third party sidecars

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Just to be clear - Lightroom (LR) uses standard XMP sidecar files for raw metadata and edits. Mylio works fine with Lightroom (arguably the most popular raw editor).

Really want sidecar files also for On1 raw to be part of backup!

To clarify that last comment regarding “On1 raw”, it doesn’t appear that the files with an “on1” extension are actually raw files or even image files but are text files that include all the camera metadata as well as the On1-specific settings applied as edits to the base image file (which in my case is a .nef Nikon RAW file). Once an image file is edited with On1, On1 creates an .on1 file and an .xmp file in the same directory as the original image.

Just to bump this along. Saw this thread as I was just about to post the following:

Using Mylio 3.15 on Windows 10.

-testing with a sample of photos located on a usb drive (G:) in folder Pictures Test 1.
-created a library on G: using “Add without moving”.
-for security redundancy created a second library on J:
-ON1 sidecars in G:Pictures Test 1 were not copied/duplicated to J:
-J: cannot be considered a full, useful backup without these sidecar files (and any other app sidecar) since it contains all of the parametric edits for the source program.
-did I miss doing something; is this normal; a solution?

-This is a DEAL BREAKER without this functionality.

I also noticed that with 3.15 the designation of a drive as a “Vault” is not explicitly stated in any of the info panes. Are Vaults just inferred/automatic now?