You can just use Fine Uploader, which is an MIT licensed-library that handles direct-to-s3 uploads from the browser, with support for v2/v4 signatures, chunking

You can just use Fine Uploader, which is an MIT licensed-library that handles direct-to-s3 uploads from the browser, with support for v2/v4 signatures, chunking, pause/resume uploads, image scaling/previews, drag and drop, folder uploads, etc, etc. http://fineuploader.com/ http://fineuploader.com/