The Web server (running the Web site) thinks that the HTTP data stream sent by the client (e.g. your Web browser or our CheckUpDown robot) was simply too large i.e. too many bytes. What constitutes 'too many bytes' depends partly upon the operation being attempted. For example a request to upload a very large file (via the HTTP PUT method) may encounter a ceiling on upload file size set by the Web server.
This error seldom occurs in most Web traffic, particularly when the client system is a Web browser. The problem can only be resolved by examining what your client system is trying to do then discussing with your ISP why the Web server rejects the number of bytes sent by the client system.
Our service monitors your site for HTTP errors like 413. This error should simply never occur on your CheckUpDown account. If it does, it typically indicates defective programming of our systems or of the Web server which manages the site. The length of the HTTP data stream we normally send is relatively small and well within the limits of what most Web servers should accept.
Please contact us (email preferred) whenever you encounter 413 errors - there is nothing you can do to sort them out. We then have to liaise with your ISP and the vendor of the Web server software to agree the exact reason for the error.
Any client (e.g. your Web browser or our CheckUpDown robot) goes through the following cycle when it communicates with the Web server:
This error occurs in the final step above when the client receives an HTTP status code that it recognises as '413'.