client side PHP validation

Is there any website that has something like you put in your PHP code, and it says whether it would work at runtime?

You mean a PHP interpreter?
http://www.php.net/downloads.phphttp://www.google.com/search?q=php+hosting

I'm looking for a site where I can paste my PHP code and it will tell me whether there are any parsing or syntax or other errors. So that I DON"T have to upload it to a host.

www.w3schools.com find a try it yourself page, it allows you to pop your code in click submit and on half of the page it shows your result!

wow I didn't think of that