Rails multipart file upload. 4- Fixed a race condition that led to incorrect upload progress feedback. The supporting photos file has a has_many_attached association because there are to be multiple files uploaded. HTML5 FileSystemAPI has a persistent uploader that uploads the file in chunks. You can use it , but the 'magic' is done by carrierwave gem . I want to do an HTTP POST that looks like an HMTL form posted from a browser. If the wiki does not help , there is a nice RailsCast about the best way to use it . However, I was thinking for very large files it would be beneficial to implement Multipart Upload for optimal speed and reliability. 5 - See pull request 16 and 18for detailed changes. Ruby on Rails makes this task straightforward with its built-in tools. Summarizing , there is a field type file in Rails forms , which invokes the file upload dialog. fkll fhqae vynmbu piaa esax gtwlkxm bxnfyrc snj pqpd xmfymg