The image should show up on Firefox's download list. You should look into the Download folder and open an image from the list, does it displaying the image and let you see the path ? You can also check the main Android Downloads folder, it is because it would be a logical place for them to be saved. In my case, when I look at a saved image on my device in the Gallery app and tap Details, it shows me: /SD card/Android/data/org.mozilla.firefox/files/Download So if you have a file viewer, you can check over there.