Maximum length of URL fragments (hash)

It depends on the browser. I found that in safari, chrome, and Firefox, an URL with a long hash is legal, but if it is a param send to the server, the browser will display an 414 or 413 error.

for example: an URL like http://www.stackoverflow.com/?abc#{hash value with 100 thousand characters} will be ok. and you can use location.hash to get the hash value in javascript but an URL like http://www.stackoverflow.com/?abc&{query with 100 thousand characters} will be illegal, if you paste this link in the address bar, a 413 error code will be given and the message is the client issued a request that was too long. If that is a link in a web page, in my computer, Nginx response the 414 error message.

I don't know the situation in IE.

So I think, the limitation of the length of URL is just for transmission or HTTP server, the browser will check it sometimes, but not every time, and it will always be allowed to be used as a hash.

There is definitely a length for the whole url.

Read

RFC2616 - Hypertext Transfer Protocol

Maximum URL length is 2,083 characters in Internet Explorer

The hash is client side only, so the rules for HTTP may not apply to it.