URL encode space to '%20' instead of '+'

Question

Is there a way to prevent the browser from url-encoding a space to "+" and encode to "%20" instead? Just by modifying the input.

e.g. something like <iframe{some_special_character}src="http://www.example.com/index.php"> where some_special_character when url encoded will give '%20' instead of '+'.

some_special_character is the answer I'm interested in.

Answer 1

It turns out that

<iframe
src="http://www.example.com/index.php">

will skip the space entirely, so my problem disappeared all of a sudden.