Hi

Thank you for your question, something that I have been speaking to the Firefox for Android developers about.

Firefox for Android does support permissions to write to the SD card, but only if you are using the default system Downloads directory. Right now there is no scope for adding any additional support, but this is something that may be considered in the future. Also worth mentioning that Android does restrict us to specific directories which makes it difficult to support downloads in other locations.

If you wanting to look into this in more depth, I recommend that you consult a specialist Android support team

What I'm talking about is writing to an external SD card that on recent Android versions gets mounted as external data storage. The internal storage of an Android phone gets emulated as an SD card on recent versions of Android and dealing with the internal storage/internal SD card is not an issue. Using the about:config trick here , I can download to any location I want on the internal storage just fine (/sdcard/ is linked to the internal storage that's emulated as an SD card and is the same as /storage/emulated/0/). It's just that if I point to any location on the external SD card (on Android 6.0 Marshmallow, it shows up like /storage/17E4-031F/), all downloads go to the Download folder on the internal storage.

I know that at least on Android 6.0 Marshmallow (maybe Android 5 Lollipop as well), the permissions have changed a bit such that an app can request write access to the external storage. I've seen it occur in some updated apps where the app would launch a file browser and ask to navigate to and select the root of the external storage/external sd card in order to get write access to it. An example app that can show this is the QuickPic Gallery app by Cheetah Mobile Cloud as it needs the permission to access the external storage/sd card in order to move/delete pictures to/from the external storage.

I have got this problem, too. I am using the German Cliqz browser in parallel which allows to change the download location easily: An Android internal file browser is launched which allows to select and set the new destination folder. This seems to be a standard Android function from version 6 and higher. Other apps launch this file browser at installation time in order to allow to store big databases on external sdcard.

To be even more precise: This Android file browsers dialog not only sets a folder location but additionally grants write access for the app to exactly the selected folder.

It should not be such an issue to integrate this functionality.