This JavaScript File Upload example demonstrates how to add an image preview of the uploaded files. Browse or drag-and-drop image files (PNG, JPG) to display preview for the selected files.
The Uploader control allows to create preview images after uploaded it. The preview images created by reading the file using success event. Also, the user can create preview images before uploading to server using select event. For more information, you can refer to the Image Preview section from this documentation section.