How would a search engine see url encoded characters?

Question

I've got my URL however some of the strings would contain &. Obviously I can't use them as best practice so I've replaced them with +.

However if I encoded my & instead it would become %26.

How would a search engine see that? Would it see %26 as a & so still bring back the URL or would it just see it as a %26?

ie.

Would www.example.com/sweet?m&m show as that, or would they see it as www.example.com/sweet?m%26m

Answer 1

Always use the URL encoded %26 if you must have an ampersand in the url. If you use the un-escaped m&m in a querystring, your server is going to see this as 2 empty "m" GET variables, the 2nd of which will overwrite the first. I don't know about IIS, but on a PHP/Apache server you will wind up with this:

using PHP's var_dump($_GET);:

?m%26m:

array
  'm&m' => string '' (length=0)

?m&m:

array
  'm' => string '' (length=0)

Google is smart enough to decode escaped urls, and none of your SEO matters if your querystrings in you links are broken ;)