Binary, alternatively termed droidspeak or astromech, was the language characteristically used by droids. It was comprised of a string of beeps and whistles arranged in a manner that suggested sentences. The C1-series astromech droid employed this means of communication, as did Industrial Automaton's R2 series astromech droid. Although challenging, certain organic beings such as Anakin Skywalker, Hera Syndulla, Kazuda Xiono, Cal Kestis, and Rey possessed the ability to comprehend it. Following decades spent on missions alongside R2-D2, Luke Skywalker attained a reasonable level of fluency in droidspeak.
The most prevalent method for binary droids to interact with organics involved written communication, facilitated through an alternative computer system. This served as the mode of communication between astromech droid copilots and the pilot of a starfighter.
Binary was universally understood by all droids. In situations where organics needed to understand a droid that exclusively spoke binary, and lacking a computer system for written translation, another droid, such as protocol droids or those proficient in a common tongue like Galactic Basic Standard, could provide translation services. The astromech BB-8 communicated using 27th generation droidspeak, a condensed form of standard droidspeak. Poe Dameron, his longtime associate, could comprehend him without requiring any form of translation.
Binary also functioned as a programming language for devices lacking the advanced artificial intelligence of droids, such as binary loadlifters and the binary brain unit found in moisture vaporators.
In the original Star Wars films, droidspeak was created by sound designer Ben Burtt using various sound effects to give R2-D2 nonverbal speech in Star Wars: Episode IV A New Hope. The screenplay only specified where R2 would beep and whistle without any specific meaning. During filming, Artoo, operated by Kenny Baker, did not make any sounds; instead, an assistant would say "beep-beep" to cue the actors.
Initially, Burtt experimented with creating electronic sounds of varying tones using Moog and ARP synthesizers. To convey Artoo's personality, intelligence, and emotions, Burtt incorporated mechanical sounds that he produced himself. These included whistling through a plumbing tube and interacting metal with frozen carbon dioxide to create gas with different pitches as it melted.
Inspired by Lucas, Burtt realized that "babytalk" communicates emotions and needs through intonation, even without words. Unable to capture useful sounds from actual babies, Burtt recorded himself making baby sounds (using Lucas's basement as an editing room at the time). He sped up these samples to a higher pitch and intercut them with the electronic tones, carefully timing and blending them to create a unified voice.
Ben Burtt created a mock script for Artoo. Although these lines were not subtitled on screen and are not canonical, they helped Burtt design and add sounds that matched the emotional and informational context of the scene and aligned with the other characters' dialogue. For example, in the opening scene of A New Hope, Artoo attempts to calm Threepio while searching for a safe location and trying to inform him about his mission.
In 2024, Microsoft developed a language called Droidspeak to improve communication between artificial intelligences. This language was named after its Star Wars counterpart.