A 413 Payload Too Large error (historically called Request Entity Too Large) occurs when the request sent by your web browser or client is larger than the server is willing or configured to process. This most commonly happens when uploading large files, photos, or videos that exceed server upload limits.
Common causes
A 413 Request Entity Too Large error occurs when a request made from a client is too large to be processed by the web server.
Cloudflare can also return the error if the request was to large.
An example request, that may cause this error would be if you were trying to upload a very large file to the server.
Resolution
You can “pause” Cloudflare to temporarily work around the request size limitation. Be aware that doing so will cause Cloudflare’s SSL to stop working for the site.