Empty characters, blank characters, invisible characters and whitespace characters. They look like a space, but are in fact a different (unicode) character. They can be used if you want to represent an empty space without using space. Let’s say you want to use an empty value in a website or application, but spaces are not accepted. For this situation you can use one of the characters on this site. For example, sending an empty message, or setting a form value to blank. If the application filters out other unicode characters then the characters on this site might not work.