HTTP Error 414 Request URI too long

Introduction

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) contains a URL that is simply too large i.e. too many bytes.

Typically Web servers set fairly generous limits on length for genuine URLs e.g. up to 2048 or 4096 characters. If your URL is particularly long, you can usually try shorter variations to see roughly where the limit is. If your long URL is indeed valid, then the Web server may need to be reconfigured to allow your URLs through. Understand that Web servers have to set some reasonable limit here, because they have to deal with badly programmed clients trying to give them huge garbage URLs.

414 errors in the HTTP cycle

Any client (e.g. your Web browser or our CheckUpDown robot) goes through the following cycle:

• Obtain an IP address from the IP name of the site (the site URL without the leading 'http://'). This lookup (conversion of IP name to IP address) is provided by domain name servers (DNSs).
• Open an IP socket connection to that IP address.
• Write an HTTP data stream through that socket.
• Receive an HTTP data stream back from the Web server in response. This data stream contains status codes whose values are determined by the HTTP protocol. Parse this data stream for status codes and other useful information.

This error occurs in the final step above when the client receives an HTTP status code that it recognises as '414'.

Fixing 414 errors - general

This error seldom occurs in most Web traffic, particularly when the client system is a Web browser. The URLs in this case are typically standard hyperlinks found on Web pages. These links tend to be too large if they are simply wrong i.e. the Web page containing the link has been badly coded.

If your client system is not a Web browser, the problem can only be resolved by examining what the client is trying to do then discussing with your ISP why the Web server rejects the size of the URL sent by the client system.

Fixing 414 errors - CheckUpDown

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 URL we send in the HTTP data stream is typically relatively small and well within the limits of what most Web servers should accept. You can test this for yourself by simply keying the URL into any Web browser.

Please contact us (email preferred) whenever you encounter 414 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.