Folder uploads are not officially supported due to browser limitations. However, there are alternative ways which will make the process of uploading images into multiple Sets faster.
Multiple Tabs Alternative
You can open multiple tabs in your browser, and upload each folder into the respective Sets at the same time.
1. Click on +Add Set to create and name your Sets according to how your folders are organized.
2. Open Multiple Tabs in your browser (If you are using Chrome, press "cmd + T" or "command + T" on a Mac, or use "CTRL + T" on a PC/Windows computer), and upload images into the respective Sets at the same time.
1. Upload all of your images into a single Set (you can use the default Highlights Set); once the upload process is complete, you can select images to Move or Copy them to other Photo Sets as needed.
2. Create your Photo Set names before beginning the selection process:
3. To select multiple images at once, click on the thumbnail of the image and hold and drag across images you would like included in your selection. You can also hold the shift key and click to select multiple rows of images, or simply click on any of the individual images you want to select.
4. Once you have made your selection, you can move the images to the desired Sets that you created in step 2. Click the Move/Copy button, and select which Set you would like to move or copy the image(s) to.
You can then repeat this process until you have moved all your pictures to their desired Sets!