You'll want to read http://dev.w3.org/2006/webapi/FileAPI/#creating-revoking http://dev.w3.org/2006/webapi/FileAPI/#creating-revoking and use BlobBuilder.js (ht

You'll want to read http://dev.w3.org/2006/webapi/FileAPI/#creating-revoking http://dev.w3.org/2006/webapi/FileAPI/#creating-revoking and use BlobBuilder.js (https://github.com/eligrey/BlobBuilder.js https://github.com/eligrey/BlobBuilder.js) to smooth out the inconsistencies (e.g. createObjectURL is on window on older WebKits) and add BlobBuilder support to browsers that only support data: URIs.