10.12. URL and Query String Length

Previously ASP.NET limited accepted URLs to a maximum of 260 characters (an NTFS constraint). ASP.NET 4.0 allows you to extend (or limit) the URL and query string maximum length. To modify these settings, change the maxRequestPathLength and maxQueryStringLength properties (in the httpRuntime section) in Web.config:

<httpRuntime maxQueryStringLength="260" maxRequestLength="2048"/>