What do you mean exactly?

You mean

Route::get('asldkfjasdklfjkaslfdjkalsfjdksladjfsadlkfjasdklfasdfasdflkasjdfklsadjfklasdjfklsadjfklsadjfsadlkfjasklfjaskljfklasjflkasdjfklsadjfklasjflksadjflksadjflasdkjfaslkfjasdkljfasdlfasdjlfjasldfas', function() {

});

something like this?

I had this issue when I was working on a java project with a tomcat. I had to change a configuration. I don't really remember what it was.

Googling shows that some other people are having the exact same issues. One of them is https://code.google.com/p/modpagespeed/issues/detail?id=176

Search keywords: "apache get 256 limitation", "apache get request 256", "apache query string length"

You might want to check your server configuration and check to see if there are any plugins/extensions that might cause this issue.

I ran a simple test on my mamp setup and I was able to replicate your issue as well. 255 characters work just fine.

It's not Laravel issue really. I get 403 forbidden error when I pass 256 characters, meaning that my apache isn't sending data to Laravel.