Depending on the plan your domain is subscribed to, CloudFlare limits data uploads to the following sizes:
100MB Free
100MB Pro
200MB Business
500MB Enterprise
The upload limits apply only if you have CloudFlare enabled (Orange cloud next to the DNS records on the DNS settings page). For example, if your domain is subscribed to the Pro plan, a visitor to your website can upload data up to 100MB, per request. This limit overrides any upload limit you may have set over a 100MB at your origin.