In Unicode there are a lot of invisible characters: regular white-space characters (e.g. U+0020 SPACE), language specific fillers (e.g. U+3164 HANGUL FILLER of the Korean Hangual alphabet), or special characters (e.g. U+2800 BRAILLE PATTERN BLANK). While all of these have a specific meaning in their natural context, they can be used in various applications that don't allow for regular whitespace characters.
While the popular game Among Us doesn't allow for an empty player name, or a name just containing regular space characters, you can copy and paste the U+3164 HANGUL FILLER when naming your player.
Send empty Whatsapp messages (instructions) using the U+200E LEFT-TO-RIGHT MARK.
When copy and pasting the U+200C ZERO WIDTH NON-JOINER into the title field of a Youtube video, the title becomes empty.
Send empty tweets (instructions) using the U+3164 HANGUL FILLER.
If you want to see what invisible characters are contained in a block of text, you can use our online tool to view invisible characters.