Great question!

Voice-activated virtual assistants like Alexa and Siri are electronic devices powered by artificial intelligence (AI) and natural language processing (NLP). They work by listening for a “wake word,” like "Alexa" or "Hey Siri," which activates the device’s microphone. Once activated, your spoken commands are recorded and sent to cloud servers, where advanced algorithms analyze the audio to interpret your request. These systems use vast databases and machine learning to understand context, recognize patterns, and provide accurate responses, whether playing music, answering questions, controlling smart devices, or performing tasks like setting reminders.

Like many modern technologies, these devices raise many intriguing halachic questions, such as:

  • What prohibitions (if any) are associated with their use on Shabbat?
  • Assuming that they may not be used, if one refrains from saying the wake word "Alexa" during Shabbat, may the device remain plugged in?
  • Are there any situations where its use might be permitted?

Muzzling an Animal

Since we interact with these devices through speech, the first question we need to address is whether speech is considered action. And amazingly, this question was addressed in Talmudic times.

The Torah states, “You shall not muzzle an ox when it is threshing [the grain].”1 The Talmud discusses whether one violates this prohibition if he prevents the animal from eating through a voice command (e.g., shouting whenever it tries to eat). Rabbi Yochanan maintains that even a verbal command constitutes a violation, while his student & colleague Reish Lakish disagrees. The Talmud explains that their disagreement hinges on whether a voice command is considered a deed.2

The halachah follows the opinion of Rabbi Yochanan that a voice command is considered an actionable deed.3

Thus, using a voice command to cause a device to perform an act that is forbidden on Shabbat would be a problem.

Preparing the Manna on Shabbat

We find another fascinating precedent, this time directly relating to prohibited work on Shabbat. The Talmud explains that the manna provided to our ancestors as they traversed the desert was heavenly food that could take on the flavor of any dish a person envisioned.

The commentaries raise a question: If the manna’s taste could change through thought or speech, why does the Torah4 instruct the Jewish people to prepare it—through baking and cooking—before Shabbat? Why could they not simply tell it to prepare itself on Shabbat?

The commentaries explain that even if cooking is achieved through thought, never mind speech, it’s still considered prohibited work and is therefore forbidden on Shabbat.5

Since you can’t intentionally cause a forbidden action on Shabbat, it’s clear that you can’t tell Alexa to turn up the heat, turn off the lights, or cook your soup. But what about commands that do not generate such a clearly forbidden reaction?

What About Using It to Get Information or Play Music?

It appears that simply communicating with the device and receiving a response is problematic. This is similar to (and perhaps even more problematic than) using a microphone on Shabbat.

After all, these devices work by having a microphone left on over Shabbat with a computer chip deciphering the converted electrical signals, which in turn causes the device to respond.

Contemporary rabbinic authorities prohibit the use of microphones on Shabbat for several halachic reasons, including (but not limited to):

Molid Kol (Creating Sound): The act of using a microphone involves creating a sound from one's voice, which is considered a form of "creating something new" and is therefore forbidden.6

Electricity and Circuit Completion: Some microphones rely on electrical circuits to function. Speaking into a microphone can cause electrical changes, such as completing or modifying a circuit and increasing the flow of electricity, which may constitute forbidden melachah.7

Avsha Milta (Making Noise) and Zilzul Shabbat (Degrading the Sanctity of Shabbat): Amplifying sound creates noticeable activity that contradicts the restful atmosphere of Shabbat, which should be free from unnecessary disturbances.8 (This would apply even if one theoretically solved all the other potential issues of using a microphone on Shabbat).

Shema Yetaken Kli Shir (Fixing or Assembling a Musical Instrument): There is a rabbinic prohibition against engaging with musical instruments on Shabbat due to the concern that one might repair or assemble them. Microphones, which similarly produce and amplify sound, fall under this category.9

Some of the above issues would also apply to voice-activated virtual assistants. Furthermore, unlike a microphone, these devices don’t simply amplify your voice; they respond and interact with it, making them even more problematic to use on Shabbat (aside from the fact that lights are often activated when triggering the device).

Should I Turn It Off Before Shabbat?

Based on the above, these devices should ideally be turned off before Shabbat. Why? Because you set them up with the intent that they would constantly listen to and process all spoken words, which is problematic.

If you forgot to turn them off before Shabbat, it would be preferable to avoid speaking in that room, but it would likely be permissible to talk there if needed. At that point, you don’t actually want the device to listen to your words and have no wish to trigger anything within it.