The Visitors have their own language, which is used both in their computer systems and in various signs posted around their facilities.
The Visitors have a character set consisting of forty-one characters. Each English letter is represented in their character set, along with digraphs and macrons.
- The Visitor Embassies have the text "we are of peace" written on their walls, ("A Bright New Day") as do their medical centers. ("It's Only the Beginning")
- Many signs posted around the Visitor Embassies and in the Surveillance Center are bilingual. ("A Bright New Day")
- Ryan sent the message "John May Lives" to the Mothership in both English and the Visitor's language. ("It's Only the Beginning")
- While the macrons and digraphs do appear on Visitor computer screens, they are generally absent from posted signs even when it would be appropriate to include them.
- A font of the Visitor's language is available for download from its creator's blog.
The 2009 series uses a very similar set of characters, but the characters are assigned different meanings.
The 1984 version has letters only. Most, if not all, of the readable text is displayed on computer screens. Props seem to use the same characters, but at random, often sideways or upside down and do not generally contain translatable messages.