What is the limit on QueryString / GET / URL parameters
I remember something that the standard defines 1024 bytes for URL's (including query string) but I also read somewhere that Internet Explorer accepts up to 2083 characters. Probably quite browser dependent...
There is no defined limit. However, RFC 2068 states:
The HTTP protocol does not place any a priori limit on the length of a URI. Servers MUST be able to handle the URI of any resource they serve, and SHOULD be able to handle URIs of unbounded length if they provide GET-based forms that could generate such URIs. A server SHOULD return 414 (Request-URI Too Long) status if a URI is longer than the server can handle (see section 10.4.15). Note: Servers should be cautious about depending on URI lengths above 255 bytes, because some older client or proxy implementations may not properly support these lengths.
There is no limit in theory. For HTTP URLs, the HTTP 1.1 specification states:
The HTTP protocol does not place any a priori limit on the length of a URI. Servers MUST be able to handle the URI of any resource they serve, and SHOULD be able to handle URIs of unbounded length if they provide GET-based forms that could generate such URIs. A server SHOULD return 414 (Request-URI Too Long) status if a URI is longer than the server can handle (see section 10.4.15).
But in practice, many clients and servers do only support URLs up to a certain length. The thumb of rule is not to use URLs longer than 2000 characters (percent encoding already taken into account).