The Dropbox mobile app is filling up my iPhone storage

Hi Penisoo, thanks for bringing this to our attention.

In general, when photos are uploaded to Dropbox via the Dropbox mobile app, the cache is used as an intermediary to ensure the upload is successful. 

Once the upload is done, the cache should automatically clear itself from the mobile app. In the case that it doesn't do so, you can use the iOS settings to clear the cache of the app.

If this doesn't work, the easiest solution, if you're not on a Dropbox Basic plan with more than 3 devices connected, would be to try uninstalling the app, rebooting the device, and re-installing it. This should clear up the extra storage it originally took up.

Regarding the comments, are you referring to the comments you specifically add using the Dropbox interface, and not comments attached within the file itself?

This will help me to assist further!

As I stated, the Dropbox app cache was empty and the files had been completely uploaded.  On an iPhone, the Dropbox app cache is emptied via the Dropbox app not via iOS itself.  Deleting the Dropbox app (including all of the app's documents and data) and then reinstalling the Dropbox app did clear the Camera Uploads folder - but as I stated, this is just a very crude, temporary hack since the problem remains: photos uploaded from an iPhone to Dropbox reside not only on the Dropbox cloud but also in the iPhone's Dropbox storage (in addition to in the iPhone's photo storage until permanently deleted).  Deleting the photos in the iPhone's Dropbox storage also deletes the copies in the Dropbox cloud.  Unlike on my Windows laptop, on my iPhone I cannot find a method for marking all of the Dropbox folders as online only (and for making the default online only).

I don't want the files and folders synced from the cloud to my iPhone!  (Perhaps in the future I'd want to sync selected files, but for now I'm happy to keep selected copies in my iPhone Photo Gallery rather than having "copies" in the Dropbox app that aren't really copies but still take up iPhone storage.)  Dropbox is not very useful on an iPhone if I have to reinstall the Dropbox app every time I need to clear space.

Regarding the comments, I use the iPhone Photos app to attach a note to a photo.  (Open the Photos app, open a photo, click on the 'i' at the bottom of the photo, and then enter the note in the "Add a Caption" field.)  In the Dropbox app, when I open the photo, click on "...", and then click on "Info"; I see the photo's Time, Location, Capture Details, Camera, File Info, and Image Details - but I do not see the note.  The photo is stored in Dropbox in HEIC format.

Files on the Dropbox site wouldn't take up space on your mobile app, unless you've marked them as available offline manually.

Could you check to see that you don't have the camera uploads folder set as available offline in the Dropbox mobile app settings?

Reinstalling the Dropbox app freed up just enough space for me to update iOS to version 26.3.  In the Dropbox app, the folders "Camera Uploads" and "Mobile Uploads" are empty.  In the Dropbox app, 'Camera uploads' is off, 'Manage offline files' reports 0 files, and 'Recover deleted files' reports no deleted files.  The Dropbox app cache and search history are both clear.  All of the folders are only available online.

Hey Penisoo, let me jump in here! 

Allow me to add that based on the info you provided earlier it looks like you're commenting on your files locally within your Camera roll, not within the Dropbox app. Comments won't transfer from your camera roll to Dropbox. 

You'd need to upload your files to Dropbox, then open the file you want to comment on. Click this icon (comments) in the bottom left and add a comment to an area in the file, or a precise point in the file.

Also, I'd like for you to open your iPhone's settings, then Storage and locate Dropbox there. How much space does the app occupy? Can you send me a screenshot of that, along with a couple of screenshots demonstrating the Photos folders in your Camera roll that you mentioned they take up space both locally and inside the Dropbox app? I'd like to have a visual of this too. 

Comments issue: Since I add the comment at the time of taking the photo, waiting until I've stored the photo in Dropbox and then adding the comment in the Dropbox app is a no-go.  The comments made via the Apple Photos app should be stored in Dropbox with the rest of the metadata.  Until that time, I'll use a different mechanism for backing up and storing those photos.

Dropbox storage: the Apple Photos app albums are not in Dropbox; the issue is that when I "move" a photo (or video) from the Apple Photos storage space to a specific folder in Dropbox, even though all of the folders in the Dropbox app on my iPhone are online only, after the move, and after confirming completed upload and empty cache, the photo is consuming Dropbox storage space on my iPhone as well as in the Dropbox cloud and deleting the file from Dropbox storage on my iPhone also deletes it from the Dropbox cloud.  The only way to empty the Dropbox data storage space on my iPhone but not in the Dropbox cloud is to delete and then reinstall the Dropbox app on my iPhone.

Note that the online-only function works as expected on my Windows 10 laptop: in the Dropbox app on my laptop I marked all but one folder as online only.  Then I moved a file from a non-Dropbox folder to an online folder and voila, the laptop view of the file in the Dropbox folder is an Internet shortcut while the Dropbox browser (online) view of the file has the correct metadata.  Files in the offline folder consume an equal amount of space on my laptop and on the Dropbox cloud.

Hi from me as well, Penisoo. 

Can you send us the screenshot(s) Megan asked for previously? It’ll help us to have a visual of this, in order to further investigate.

The four screen shots are a little out of order: on my iPhone the first screenshot shows the Dropbox data storage using 28MB.  I then uploaded that screen shot to my Dropbox Mobile Uploads folder.  The next screen shot shows Dropbox data using 28.4MB.  The next screen shot is of my Dropbox Mobile Uploads folder to show that the folder is set to online only.  Then I uploaded those screen shots to my Dropbox Mobile Uploads folder.  The fourth screen shot shows Dropbox data using 68.5MB on my iPhone (and once that fourth screen shot was uploaded, the data storage increased to 68.7MB.

These four screen shots were attached to this discussion comment from my laptop accessing the Dropbox online only folders.

HI Penisoo, I think it would be best to contact the support team at this point since they have more tools and steps available to troubleshoot this matter for you.
You can submit a ticket to the team via this link while logged into your Dropbox account.