Local File uploader: Up to 5GB per file
Dropbox: Up to 20 GB per file
Box: Up to 20 GB per file
Google Drive: Up to 20 GB per file
Mac App/FCPX Extension: Unlimited size
Note: max length for all files is 4 hours
Related Help Articles:
How to upload your files on Simon Says
How to use the transcript editor
Speed of Transcription & Translation
What export options do you support?
What is the accuracy of your system?
Which formats/codecs do you support?