Maximum URL length is 2,083 characters in Internet Explorer

SUMMARY

Microsoft Internet Explorer has a maximum uniform resource locator (URL) length of 2,083 characters. Internet Explorer also has a maximum path length of 2,048 characters. This limit applies to both POST request and GET request URLs.

If you are using the GET method, you are limited to a maximum of 2,048 characters, minus the number of characters in the actual path.

However, the POST method is not limited by the size of the URL for submitting name/value pairs. These pairs are transferred in the header and not in the URL.

RFC 2616, "Hypertext Transfer Protocol -- HTTP/1.1," does not specify any requirement for URL length.  

http://support.microsoft.com/default.aspx?scid=kb;EN-US;q208427