Why do you need to encode URLs?

Question

Why do you need to encode urls? Is there a good reason why you have to change every space in the GET data to %20?

Answer 1

• originally older browsers could get confused by the spaces (not really an issue anymore).
• now, if someone copies the url to send as a link - the space can break the hyperlink - ie

Hey! Check out this derping cat playing a piano!

http://www.mysite.com/?video=funny cat plays piano.

See how the link breaks?

Now look at this:

http://www.mysite.com/?video=funny%20cat%20plays%20piano.